1
|
Nafi'an MRT, Sabirin RM, Wibowo RA, Sofyana M, Zahra IH, Wiryawan DA, Wijayatno QJ, Rohman A. Effect of Nitrate Supplementation on Oxygen Saturation Levels for Acute Mountain Sickness Prevention: A Systematic Review and Meta-Analysis. Nitric Oxide 2024:S1089-8603(24)00083-1. [PMID: 39002891 DOI: 10.1016/j.niox.2024.07.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Revised: 05/27/2024] [Accepted: 07/04/2024] [Indexed: 07/15/2024]
Abstract
PURPOSE This study aimed to systematically review the effect of nitrate supplementation on blood oxygen saturation. METHODS We searched PubMed, Scopus, and Cochrane Library databases from their inception up to October 2022. Two reviewers independently conducted two stages of the screening process to include a randomized controlled trial with nitrate supplementation versus placebo intervention assessing oxygen saturation among lowlanders going to either real or simulated high altitude environments. We used the Cochrane Risk of Bias 2.0 tool to assess the risk of bias in the included studies. Fixed-effect model meta-analyses were conducted for laboratory-based studies. Random-effect meta-analyses were conducted for real-world studies. RESULTS We found 7 trials that met the eligibility criteria. A meta-analysis of studies with some bias concerns showed an increase of 1.26% in the SpO2 with 44% I2 during submaximal exercise at simulated high altitudes (GRADE: low). On the contrary, a meta-analysis of studies without heterogeneity showed that nitrate supplementation aggravated oxygen saturation decline (-2.64%, p=0.03, GRADE: high) during rest in real high-altitude environments. A meta-analysis also showed that nitrate supplementation did not affect Acute Mountain Sickness (AMS) symptoms (GRADE: high). CONCLUSION Our results suggest that nitrate supplementation did not provide benefits for AMS prevention during rest at high altitudes. The low-quality evidence showing small beneficial effects of nitrate supplementation during exercise calls for further studies.
Collapse
Affiliation(s)
| | - Rahmaningsih Mara Sabirin
- Department of Physiology, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Jakarta, Indonesia.
| | - Rakhmat Ari Wibowo
- Department of Physiology, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Jakarta, Indonesia; Physical Activity for Health Research Centre, Institute of Sport, Physical Education, and Health Sciences, Moray House School of Education and Sport, University of Edinburgh, Edinburgh, UK
| | - Meida Sofyana
- Department of Physiology, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Jakarta, Indonesia; School of Physiology, Pharmacology, & Neuroscience, University of Bristol, Bristol, England, UK
| | - Imtiyaz Hafizah Zahra
- School of Medicine, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Indonesia
| | - Danindra Ario Wiryawan
- School of Medicine, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Indonesia
| | - Qonita Jayanti Wijayatno
- School of Medicine, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Indonesia
| | - Abdul Rohman
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Universitas Gadjah Mada, Yogyakarta, 55281, Indonesia
| |
Collapse
|
2
|
Su R, Jia S, Zhang N, Wang Y, Li H, Zhang D, Ma H, Su Y. The effects of long-term high-altitude exposure on cognition: A meta-analysis. Neurosci Biobehav Rev 2024; 161:105682. [PMID: 38642865 DOI: 10.1016/j.neubiorev.2024.105682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2024] [Revised: 04/14/2024] [Accepted: 04/16/2024] [Indexed: 04/22/2024]
Abstract
Long-term high altitudes (HA) exposure's impact on cognition has yielded inconsistent findings in previous research. To address this, we conducted a meta-analysis of 49 studies (6191 individuals) to comprehensively evaluate this effect. Moderating factors such as cognitive task type, altitude (1500-2500 m, 2500-4000 m, and above 4000 m), residential type (chronic and lifelong), adaptation level and demographic factors were analyzed. Cognitive tasks were classified into eight categories: perceptual processes, psychomotor function, long-term memory, working memory, inhibitory control, problem-solving, language, and others. Results revealed a moderate negative effect of HA on cognitive performance (g = -.40, SE =.18, 95% CI = -.76 to -.05). Psychomotor function and long-term memory notably experience the most pronounced decline, while working memory and language skills show moderate decreases due to HA exposure. However, perceptual processes, inhibitory control, and problem-solving abilities remain unaffected. Moreover, residing at altitudes above 4000 m and being a HA immigrant are associated with significant cognitive impairment. In summary, our findings indicate a selective adaptation of cognitive performance to HA conditions.
Collapse
Affiliation(s)
- Rui Su
- School of Psychological and Cognitive Sciences and Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing 100871, China; Key Laboratory of High Altitudes Brain Science and Environmental Acclimation, Tibet University, Lhasa 85000, China
| | - Shurong Jia
- Key Laboratory of High Altitudes Brain Science and Environmental Acclimation, Tibet University, Lhasa 85000, China
| | - Niannian Zhang
- Key Laboratory of High Altitudes Brain Science and Environmental Acclimation, Tibet University, Lhasa 85000, China
| | - Yiyi Wang
- Department of Psychology, University of Chicago, Chicago, IL 60637, United States
| | - Hao Li
- Key Laboratory of High Altitudes Brain Science and Environmental Acclimation, Tibet University, Lhasa 85000, China
| | - Delong Zhang
- Key Laboratory of High Altitudes Brain Science and Environmental Acclimation, Tibet University, Lhasa 85000, China; School of Psychology, Center for Studies of Psychological Application, and Guangdong Key Laboratory of Mental Health and Cognitive Science, South China Normal University, Guangzhou, China
| | - Hailin Ma
- Key Laboratory of High Altitudes Brain Science and Environmental Acclimation, Tibet University, Lhasa 85000, China
| | - Yanjie Su
- School of Psychological and Cognitive Sciences and Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing 100871, China.
| |
Collapse
|
3
|
Liu X, Tang J, Long W, Zou Y, Tan J. Comparison of physical activity and physical fitness in children and adolescents of Chinese Han and Tibet ethnicity. Front Public Health 2024; 12:1392803. [PMID: 38784594 PMCID: PMC11111887 DOI: 10.3389/fpubh.2024.1392803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Accepted: 04/23/2024] [Indexed: 05/25/2024] Open
Abstract
Background Physical activity (PA) and physical fitness (PF) are important markers of health status in children and adolescents in different ethnicities. In this study, we aimed to compare the PA and PF indicators between Tibetan and Han children and adolescents. Methods Children and adolescents of 4-9 grades were recruited in Shigatse (n = 963) and Shanghai (n = 2,525) respectively. The information related to demographic, PA, and PF was collected via a self-reported questionnaire. PA was assessed through the participation of moderate to vigorous PA (MVPA), muscle-strengthening exercise (MSE) and organized sport participation (OSP). PF was estimated using the International Fitness Scale containing components of overall fitness, cardiorespiratory fitness, speed and agility, muscular strength and flexibility. Results Han (mean age = 13.45 ± 3.3 years; 49.7% girls) and Tibet (mean age = 13.8 ± 2.5 years; 48.3% girls) children and adolescents from Shanghai and Shigatse completed the questionnaire survey. It was revealed that Tibetan students had higher MVPA, MSE and OSP than children and adolescents of Han ethnicity (p < 0.01, small to medium effect size). A relatively higher percentage of student in Shanghai did not participate in any form of PA. On the other hand, less Tibetan students thought their PF indicators including overall fitness, cardiorespiratory fitness, speed and agility, muscular strength and flexibility were poor or very poor than their counterparts of Han ethnicity (p < 0.01, small to medium effect size). Conclusion Tibetan children and adolescents have higher levels of PA and PF in comparison to their Han counterparts. More children and adolescents of Han ethnicity engage in no PA and think their PF indicators were poor.
Collapse
Affiliation(s)
- Xiaodi Liu
- School of Physical Science and Technology, Ningbo University, Ningbo, China
| | - Jiaxing Tang
- School of Physical Education, Shanghai University of Sport, Shanghai, China
| | - Weixuan Long
- Department of Sports Science, College of Education, Zhejiang University, Hangzhou, China
| | - Yu Zou
- Department of Sports Science, College of Education, Zhejiang University, Hangzhou, China
| | - Jingwang Tan
- Department of Sports Science, College of Education, Zhejiang University, Hangzhou, China
| |
Collapse
|
4
|
Simpson LL, Stembridge M, Siebenmann C, Moore JP, Lawley JS. Mechanisms underpinning sympathoexcitation in hypoxia. J Physiol 2024. [PMID: 38533641 DOI: 10.1113/jp284579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Accepted: 02/28/2024] [Indexed: 03/28/2024] Open
Abstract
Sympathoexcitation is a hallmark of hypoxic exposure, occurring acutely, as well as persisting in acclimatised lowland populations and with generational exposure in highland native populations of the Andean and Tibetan plateaus. The mechanisms mediating altitude sympathoexcitation are multifactorial, involving alterations in both peripheral autonomic reflexes and central neural pathways, and are dependent on the duration of exposure. Initially, hypoxia-induced sympathoexcitation appears to be an adaptive response, primarily mediated by regulatory reflex mechanisms concerned with preserving systemic and cerebral tissue O2 delivery and maintaining arterial blood pressure. However, as exposure continues, sympathoexcitation is further augmented above that observed with acute exposure, despite acclimatisation processes that restore arterial oxygen content (C a O 2 ${C_{{\mathrm{a}}{{\mathrm{O}}_{\mathrm{2}}}}}$ ). Under these conditions, sympathoexcitation may become maladaptive, giving rise to reduced vascular reactivity and mildly elevated blood pressure. Importantly, current evidence indicates the peripheral chemoreflex does not play a significant role in the augmentation of sympathoexcitation during altitude acclimatisation, although methodological limitations may underestimate its true contribution. Instead, processes that provide no obvious survival benefit in hypoxia appear to contribute, including elevated pulmonary arterial pressure. Nocturnal periodic breathing is also a potential mechanism contributing to altitude sympathoexcitation, although experimental studies are required. Despite recent advancements within the field, several areas remain unexplored, including the mechanisms responsible for the apparent normalisation of muscle sympathetic nerve activity during intermediate hypoxic exposures, the mechanisms accounting for persistent sympathoexcitation following descent from altitude and consideration of whether there are sex-based differences in sympathetic regulation at altitude.
Collapse
Affiliation(s)
- Lydia L Simpson
- Department of Sport Science, Performance Physiology and Prevention, Universität Innsbruck, Innsbruck, Austria
| | - Mike Stembridge
- Cardiff School of Sport and Health Sciences, Cardiff Metropolitan University, Cardiff, UK
| | | | - Jonathan P Moore
- School of Psychology and Sport Science, Institute of Applied Human Physiology, Bangor University, Bangor, UK
| | - Justin S Lawley
- Department of Sport Science, Performance Physiology and Prevention, Universität Innsbruck, Innsbruck, Austria
- Institute of Mountain Emergency Medicine, EURAC Research, Bolzano, Italy
| |
Collapse
|
5
|
She H, Hao Y, Song G, Luo X, Lei F, Zhai W, Qu Y. Gene expression plasticity followed by genetic change during colonization in a high-elevation environment. eLife 2024; 12:RP86687. [PMID: 38470231 DOI: 10.7554/elife.86687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/13/2024] Open
Abstract
Phenotypic plasticity facilitates organismal invasion of novel environments, and the resultant phenotypic change may later be modified by genetic change, so called 'plasticity first.' Herein, we quantify gene expression plasticity and regulatory adaptation in a wild bird (Eurasian Tree Sparrow) from its original lowland (ancestral stage), experimentally implemented hypoxia acclimation (plastic stage), and colonized highland (colonized stage). Using a group of co-expressed genes from the cardiac and flight muscles, respectively, we demonstrate that gene expression plasticity to hypoxia tolerance is more often reversed than reinforced at the colonized stage. By correlating gene expression change with muscle phenotypes, we show that colonized tree sparrows reduce maladaptive plasticity that largely associated with decreased hypoxia tolerance. Conversely, adaptive plasticity that is congruent with increased hypoxia tolerance is often reinforced in the colonized tree sparrows. Genes displaying large levels of reinforcement or reversion plasticity (i.e. 200% of original level) show greater genetic divergence between ancestral and colonized populations. Overall, our work demonstrates that gene expression plasticity at the initial stage of high-elevation colonization can be reversed or reinforced through selection-driven adaptive modification.
Collapse
Affiliation(s)
- Huishang She
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Yan Hao
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Gang Song
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Xu Luo
- Faculty of Biodiversity and Conservation, Southwest Forestry University, Kunming, China
| | - Fumin Lei
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
- Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming, China
| | - Weiwei Zhai
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
- Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming, China
| | - Yanhua Qu
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| |
Collapse
|
6
|
Ren XW, Chen K, Wu J, Yang ZL, Ji T, Zhang QH. Distinctive biochemistry profiles associated with hyperuricemia between Tibetans and Hans in China. Front Endocrinol (Lausanne) 2023; 14:1229659. [PMID: 38089618 PMCID: PMC10715267 DOI: 10.3389/fendo.2023.1229659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Accepted: 10/23/2023] [Indexed: 12/18/2023] Open
Abstract
Purpose We sought to identify distinct risk factors for hyperuricemia in native Tibetan and immigrant Han populations in Tibet, China. Methods Three cohorts of male participants aged between 20 and 40 years were enrolled in this study. Biochemical parameters including serum uric acid (UA), fasting plasma glucose, insulin, lactate dehydrogenase (LDH), thyroxin, blood cell count, aminotransferase, and lipid profiles were analyzed. The association of risk factors with UA levels was evaluated using a multivariable line regression model. The effect of UA level on the biochemical parameters between the Hans and Tibetans was evaluated by two-way ANOVA. Results The prevalence of hyperuricemia (≥420 μmol/L) was 24.8% (62/250) in the Hans, similar to 23.8% (29/136) in the Tibetans. In the regression analysis, the risk factors that were significantly associated with UA in Hans did not apply to Tibetans. Tibetans had higher fasting insulin (P<0.05) and LDH (P<0.01) levels, in contrast with lower levels of triglycerides (P<0.05), total cholesterol (P<0.01), and low-density lipoprotein-cholesterol (P<0.01) than Hans in normal UA populations. Biochemistry analysis revealed lower albumin levels (P<0.001) and higher levels of all aminotransaminase and especially alkaline phosphatase (P<0.01) in Tibetans than in Hans in both populations. Compared with Hans, Tibetans had lower serum levels of urea, creatinine, and electrolytes in the normal UA population, which were further exacerbated in the high UA population. Tibetans had comparable white blood cell counts as Hans in both normal and high UA populations. In contrast, the red blood cell count and hemoglobin concentration were much lower in Tibetans than in Hans under high UA conditions. Conclusions The distinctive biochemistry between Tibetans and Hans may underlie the different etiologies of hyperuricemia in Tibet, China.
Collapse
Affiliation(s)
- Xue-Wen Ren
- Department of Emergency Medicine, First Medical Center of General Hospital of Chinese People’s Liberation Army, Beijing, China
| | - Kang Chen
- Department of Endocrinology, First Medical Center of General Hospital of Chinese People’s Liberation Army, Beijing, China
| | - Jue Wu
- Translational Medicine Research Center, General Hospital of Chinese People’s Liberation Army, Beijing, China
| | - Zhang-Lin Yang
- Department of Emergency Medicine, First Medical Center of General Hospital of Chinese People’s Liberation Army, Beijing, China
| | - Tao Ji
- Department of Emergency Medicine, First Medical Center of General Hospital of Chinese People’s Liberation Army, Beijing, China
| | - Qing-Hong Zhang
- Trauma Repair and Tissue Regeneration Center, Department of Medical Innovation Study, General Hospital of Chinese People’s Liberation Army, Beijing, China
| |
Collapse
|
7
|
Zhao Y, Xiong W, Li C, Zhao R, Lu H, Song S, Zhou Y, Hu Y, Shi B, Ge J. Hypoxia-induced signaling in the cardiovascular system: pathogenesis and therapeutic targets. Signal Transduct Target Ther 2023; 8:431. [PMID: 37981648 PMCID: PMC10658171 DOI: 10.1038/s41392-023-01652-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 09/10/2023] [Accepted: 09/13/2023] [Indexed: 11/21/2023] Open
Abstract
Hypoxia, characterized by reduced oxygen concentration, is a significant stressor that affects the survival of aerobic species and plays a prominent role in cardiovascular diseases. From the research history and milestone events related to hypoxia in cardiovascular development and diseases, The "hypoxia-inducible factors (HIFs) switch" can be observed from both temporal and spatial perspectives, encompassing the occurrence and progression of hypoxia (gradual decline in oxygen concentration), the acute and chronic manifestations of hypoxia, and the geographical characteristics of hypoxia (natural selection at high altitudes). Furthermore, hypoxia signaling pathways are associated with natural rhythms, such as diurnal and hibernation processes. In addition to innate factors and natural selection, it has been found that epigenetics, as a postnatal factor, profoundly influences the hypoxic response and progression within the cardiovascular system. Within this intricate process, interactions between different tissues and organs within the cardiovascular system and other systems in the context of hypoxia signaling pathways have been established. Thus, it is the time to summarize and to construct a multi-level regulatory framework of hypoxia signaling and mechanisms in cardiovascular diseases for developing more therapeutic targets and make reasonable advancements in clinical research, including FDA-approved drugs and ongoing clinical trials, to guide future clinical practice in the field of hypoxia signaling in cardiovascular diseases.
Collapse
Affiliation(s)
- Yongchao Zhao
- Department of Cardiology, Affiliated Hospital of Zunyi Medical University, Zunyi, 563000, China
- Department of Cardiology, Zhongshan Hospital, Fudan University, Shanghai Institute of Cardiovascular Diseases, Shanghai, 200032, China
| | - Weidong Xiong
- Department of Cardiology, Affiliated Hospital of Zunyi Medical University, Zunyi, 563000, China
- Department of Cardiology, Zhongshan Hospital, Fudan University, Shanghai Institute of Cardiovascular Diseases, Shanghai, 200032, China
- Key Laboratory of Viral Heart Diseases, National Health Commission, Shanghai, 200032, China
- Key Laboratory of Viral Heart Diseases, Chinese Academy of Medical Sciences, Shanghai, 200032, China
| | - Chaofu Li
- Department of Cardiology, Affiliated Hospital of Zunyi Medical University, Zunyi, 563000, China
- Department of Cardiology, Zhongshan Hospital, Fudan University, Shanghai Institute of Cardiovascular Diseases, Shanghai, 200032, China
| | - Ranzun Zhao
- Department of Cardiology, Affiliated Hospital of Zunyi Medical University, Zunyi, 563000, China
| | - Hao Lu
- Department of Cardiology, Zhongshan Hospital, Fudan University, Shanghai Institute of Cardiovascular Diseases, Shanghai, 200032, China
- National Clinical Research Center for Interventional Medicine, Shanghai, 200032, China
- Shanghai Clinical Research Center for Interventional Medicine, Shanghai, 200032, China
| | - Shuai Song
- Department of Cardiology, Zhongshan Hospital, Fudan University, Shanghai Institute of Cardiovascular Diseases, Shanghai, 200032, China
- National Clinical Research Center for Interventional Medicine, Shanghai, 200032, China
- Shanghai Clinical Research Center for Interventional Medicine, Shanghai, 200032, China
| | - You Zhou
- Department of Cardiology, Zhongshan Hospital, Fudan University, Shanghai Institute of Cardiovascular Diseases, Shanghai, 200032, China
- National Clinical Research Center for Interventional Medicine, Shanghai, 200032, China
- Shanghai Clinical Research Center for Interventional Medicine, Shanghai, 200032, China
| | - Yiqing Hu
- Department of Cardiology, Zhongshan Hospital, Fudan University, Shanghai Institute of Cardiovascular Diseases, Shanghai, 200032, China.
| | - Bei Shi
- Department of Cardiology, Affiliated Hospital of Zunyi Medical University, Zunyi, 563000, China.
| | - Junbo Ge
- Department of Cardiology, Affiliated Hospital of Zunyi Medical University, Zunyi, 563000, China.
- Department of Cardiology, Zhongshan Hospital, Fudan University, Shanghai Institute of Cardiovascular Diseases, Shanghai, 200032, China.
- Key Laboratory of Viral Heart Diseases, National Health Commission, Shanghai, 200032, China.
- Key Laboratory of Viral Heart Diseases, Chinese Academy of Medical Sciences, Shanghai, 200032, China.
- National Clinical Research Center for Interventional Medicine, Shanghai, 200032, China.
- Shanghai Clinical Research Center for Interventional Medicine, Shanghai, 200032, China.
- Institutes of Biomedical Sciences, Fudan University, Shanghai, 200032, China.
| |
Collapse
|
8
|
Lundberg JO, Weitzberg E. Is nitric oxide a clue to endemic goitre in highlanders? Thyroid Res 2023; 16:41. [PMID: 37784194 PMCID: PMC10546752 DOI: 10.1186/s13044-023-00183-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Accepted: 09/24/2023] [Indexed: 10/04/2023] Open
Abstract
Goitre is commonly caused by a lack of iodine in the diet. This condition is particularly prevalent in high-altitude areas where iodine deficiency is common. Here we speculate that inorganic nitrate, the oxidation product of nitric oxide, which is generated endogenously at very high levels in highlanders, further increases the risk of goitre and thyroid dysfunction in this population by inhibiting the transport of iodide into the thyroid gland. Indeed, it is well-known that nitrate and iodide compete for such transport. While iodine scarcity is a primary cause of goitre, the excessive nitrate levels in highlanders may further hinder iodide transport, exacerbating the problem.
Collapse
Affiliation(s)
- Jon O Lundberg
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.
| | - Eddie Weitzberg
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| |
Collapse
|
9
|
DeMartino AW, Poudel L, Dent MR, Chen X, Xu Q, Gladwin BS, Tejero J, Basu S, Alipour E, Jiang Y, Rose JJ, Gladwin MT, Kim-Shapiro DB. Thiol-catalyzed formation of NO-ferroheme regulates intravascular NO signaling. Nat Chem Biol 2023; 19:1256-1266. [PMID: 37710075 PMCID: PMC10897909 DOI: 10.1038/s41589-023-01413-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 07/27/2023] [Indexed: 09/16/2023]
Abstract
Nitric oxide (NO) is an endogenously produced signaling molecule that regulates blood flow and platelet activation. However, intracellular and intravascular diffusion of NO are limited by scavenging reactions with several hemoproteins, raising questions as to how free NO can signal in hemoprotein-rich environments. We explore the hypothesis that NO can be stabilized as a labile ferrous heme-nitrosyl complex (Fe2+-NO, NO-ferroheme). We observe a reaction between NO, labile ferric heme (Fe3+) and reduced thiols to yield NO-ferroheme and a thiyl radical. This thiol-catalyzed reductive nitrosylation occurs when heme is solubilized in lipophilic environments such as red blood cell membranes or bound to serum albumin. The resulting NO-ferroheme resists oxidative inactivation, is soluble in cell membranes and is transported intravascularly by albumin to promote potent vasodilation. We therefore provide an alternative route for NO delivery from erythrocytes and blood via transfer of NO-ferroheme and activation of apo-soluble guanylyl cyclase.
Collapse
Affiliation(s)
- Anthony W DeMartino
- Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Laxman Poudel
- Department of Physics, Wake Forest University, Winston-Salem, NC, USA
| | - Matthew R Dent
- Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Xiukai Chen
- Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Qinzi Xu
- Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Brendan S Gladwin
- Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Jesús Tejero
- Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, USA
- Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Swati Basu
- Department of Physics, Wake Forest University, Winston-Salem, NC, USA
- Translational Science Center, Wake Forest University, Winston-Salem, NC, USA
| | - Elmira Alipour
- Department of Physics, Wake Forest University, Winston-Salem, NC, USA
| | - Yiyang Jiang
- Department of Physics, Wake Forest University, Winston-Salem, NC, USA
| | - Jason J Rose
- Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Mark T Gladwin
- Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA.
| | - Daniel B Kim-Shapiro
- Department of Physics, Wake Forest University, Winston-Salem, NC, USA.
- Translational Science Center, Wake Forest University, Winston-Salem, NC, USA.
| |
Collapse
|
10
|
Stuehr DJ, Biswas P, Dai Y, Ghosh A, Islam S, Jayaram DT. A natural heme deficiency exists in biology that allows nitric oxide to control heme protein functions by regulating cellular heme distribution. Bioessays 2023; 45:e2300055. [PMID: 37276366 PMCID: PMC10478511 DOI: 10.1002/bies.202300055] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 05/01/2023] [Accepted: 05/04/2023] [Indexed: 06/07/2023]
Abstract
A natural heme deficiency that exists in cells outside of the circulation broadly compromises the heme contents and functions of heme proteins in cells and tissues. Recently, we found that the signaling molecule, nitric oxide (NO), can trigger or repress the deployment of intracellular heme in a concentration-dependent hormetic manner. This uncovers a new role for NO and sets the stage for it to shape numerous biological processes by controlling heme deployment and consequent heme protein functions in biology.
Collapse
Affiliation(s)
- Dennis J. Stuehr
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland OH 44195 USA
| | - Pranjal Biswas
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland OH 44195 USA
| | - Yue Dai
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland OH 44195 USA
| | - Arnab Ghosh
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland OH 44195 USA
| | - Sidra Islam
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland OH 44195 USA
| | | |
Collapse
|
11
|
Jorgensen K, Song D, Weinstein J, Garcia OA, Pearson LN, Inclán M, Rivera-Chira M, León-Velarde F, Kiyamu M, Brutsaert TD, Bigham AW, Lee FS. High-Altitude Andean H194R HIF2A Allele Is a Hypomorphic Allele. Mol Biol Evol 2023; 40:msad162. [PMID: 37463421 PMCID: PMC10370452 DOI: 10.1093/molbev/msad162] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 06/15/2023] [Accepted: 07/03/2023] [Indexed: 07/20/2023] Open
Abstract
For over 10,000 years, Andeans have resided at high altitude where the partial pressure of oxygen challenges human survival. Recent studies have provided evidence for positive selection acting in Andeans on the HIF2A (also known as EPAS1) locus, which encodes for a central transcription factor of the hypoxia-inducible factor pathway. However, the precise mechanism by which this allele might lead to altitude-adaptive phenotypes, if any, is unknown. By analyzing whole genome sequencing data from 46 high-coverage Peruvian Andean genomes, we confirm evidence for positive selection acting on HIF2A and a unique pattern of variation surrounding the Andean-specific single nucleotide variant (SNV), rs570553380, which encodes for an H194R amino acid substitution in HIF-2α. Genotyping the Andean-associated SNV rs570553380 in a group of 299 Peruvian Andeans from Cerro de Pasco, Peru (4,338 m), reveals a positive association with increased fraction of exhaled nitric oxide, a marker of nitric oxide biosynthesis. In vitro assays show that the H194R mutation impairs binding of HIF-2α to its heterodimeric partner, aryl hydrocarbon receptor nuclear translocator. A knockin mouse model bearing the H194R mutation in the Hif2a gene displays decreased levels of hypoxia-induced pulmonary Endothelin-1 transcripts and protection against hypoxia-induced pulmonary hypertension. We conclude the Andean H194R HIF2A allele is a hypomorphic (partial loss of function) allele.
Collapse
Affiliation(s)
- Kelsey Jorgensen
- Department of Anthropology, University of California, Los Angeles, CA, USA
| | - Daisheng Song
- Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Julien Weinstein
- Department of Anthropology, The University of Michigan, Ann Arbor, MI, USA
| | - Obed A Garcia
- Department of Biomedical Data Science, Stanford University, Stanford, CA, USA
| | - Laurel N Pearson
- Department of Anthropology, The Pennsylvania State University, State College, PA, USA
| | - María Inclán
- División de. Estudios Políticos, Centro de Investigación y Docencia Económicas, Mexico City, CDMX, Mexico
| | - Maria Rivera-Chira
- Departamento de Ciencias Biológicas y Fisiológicas, Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Lima, Peru
| | - Fabiola León-Velarde
- Departamento de Ciencias Biológicas y Fisiológicas, Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Lima, Peru
| | - Melisa Kiyamu
- Departamento de Ciencias Biológicas y Fisiológicas, Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Lima, Peru
| | - Tom D Brutsaert
- Department of Exercise Science, Syracuse University, Syracuse, NY, USA
| | - Abigail W Bigham
- Department of Anthropology, University of California, Los Angeles, CA, USA
| | - Frank S Lee
- Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| |
Collapse
|
12
|
Graham AM, Jamison JM, Bustos M, Cournoyer C, Michaels A, Presnell JS, Richter R, Crocker DE, Fustukjian A, Hunter ME, Rea LD, Marsillach J, Furlong CE, Meyer WK, Clark NL. Reduction of Paraoxonase Expression Followed by Inactivation across Independent Semiaquatic Mammals Suggests Stepwise Path to Pseudogenization. Mol Biol Evol 2023; 40:msad104. [PMID: 37146172 PMCID: PMC10202596 DOI: 10.1093/molbev/msad104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 03/27/2023] [Accepted: 04/17/2023] [Indexed: 05/07/2023] Open
Abstract
Convergent adaptation to the same environment by multiple lineages frequently involves rapid evolutionary change at the same genes, implicating these genes as important for environmental adaptation. Such adaptive molecular changes may yield either change or loss of protein function; loss of function can eliminate newly deleterious proteins or reduce energy necessary for protein production. We previously found a striking case of recurrent pseudogenization of the Paraoxonase 1 (Pon1) gene among aquatic mammal lineages-Pon1 became a pseudogene with genetic lesions, such as stop codons and frameshifts, at least four times independently in aquatic and semiaquatic mammals. Here, we assess the landscape and pace of pseudogenization by studying Pon1 sequences, expression levels, and enzymatic activity across four aquatic and semiaquatic mammal lineages: pinnipeds, cetaceans, otters, and beavers. We observe in beavers and pinnipeds an unexpected reduction in expression of Pon3, a paralog with similar expression patterns but different substrate preferences. Ultimately, in all lineages with aquatic/semiaquatic members, we find that preceding any coding-level pseudogenization events in Pon1, there is a drastic decrease in expression, followed by relaxed selection, thus allowing accumulation of disrupting mutations. The recurrent loss of Pon1 function in aquatic/semiaquatic lineages is consistent with a benefit to Pon1 functional loss in aquatic environments. Accordingly, we examine diving and dietary traits across pinniped species as potential driving forces of Pon1 functional loss. We find that loss is best associated with diving activity and likely results from changes in selective pressures associated with hypoxia and hypoxia-induced inflammation.
Collapse
Affiliation(s)
- Allie M Graham
- Department of Human Genetics, University of Utah, Salt Lake City, UT
| | - Jerrica M Jamison
- Department of Biological Sciences, University of Toronto—Scarborough, Scarborough, Ontario, Canada
| | - Marisol Bustos
- Department of Biomedical Engineering, University of Texas—San Antonio, San Antonio, TX
| | | | - Alexa Michaels
- Graduate School of Biomedical Sciences, Tufts University, Boston, MA
- The Jackson Laboratory, Bar Harbor, ME
| | - Jason S Presnell
- Department of Human Genetics, University of Utah, Salt Lake City, UT
| | - Rebecca Richter
- Department of Medicine, Division of Medical Genetics, University of Washington, Seattle, WA
| | - Daniel E Crocker
- Department of Biology, Sonoma State University, Rohnert Park, CA
| | | | - Margaret E Hunter
- U.S. Geological Survey, Wetland and Aquatic Research Center, Gainesville, FL
| | - Lorrie D Rea
- Water and Environmental Research Center, Institute of Northern Engineering, University of Alaska—Fairbanks, Fairbanks, AK
| | - Judit Marsillach
- Department of Environmental & Occupational Health Sciences, University of Washington School of Public Health, Seattle, WA
| | - Clement E Furlong
- Department of Medicine, Division of Medical Genetics, University of Washington, Seattle, WA
- Department of Genome Sciences, University of Washington, Seattle, WA
| | - Wynn K Meyer
- Department of Biological Sciences, Lehigh University, Bethlehem, PA
| | - Nathan L Clark
- Department of Human Genetics, University of Utah, Salt Lake City, UT
| |
Collapse
|
13
|
Stacey BS, Hoiland RL, Caldwell HG, Howe CA, Vermeulen T, Tymko MM, Vizcardo‐Galindo GA, Bermudez D, Figueroa‐Mujíica RJ, Gasho C, Tuaillon E, Hirtz C, Lehmann S, Marchi N, Tsukamoto H, Villafuerte FC, Ainslie PN, Bailey DM. Lifelong exposure to high-altitude hypoxia in humans is associated with improved redox homeostasis and structural-functional adaptations of the neurovascular unit. J Physiol 2023; 601:1095-1120. [PMID: 36633375 PMCID: PMC10952731 DOI: 10.1113/jp283362] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 12/20/2022] [Indexed: 01/13/2023] Open
Abstract
High-altitude (HA) hypoxia may alter the structural-functional integrity of the neurovascular unit (NVU). Herein, we compared male lowlanders (n = 9) at sea level (SL) and after 14 days acclimatization to 4300 m (chronic HA) in Cerro de Pasco (CdP), Péru (HA), against sex-, age- and body mass index-matched healthy highlanders (n = 9) native to CdP (lifelong HA). Venous blood was assayed for serum proteins reflecting NVU integrity, in addition to free radicals and nitric oxide (NO). Regional cerebral blood flow (CBF) was examined in conjunction with cerebral substrate delivery, dynamic cerebral autoregulation (dCA), cerebrovascular reactivity to carbon dioxide (CVRCO2 ) and neurovascular coupling (NVC). Psychomotor tests were employed to examine cognitive function. Compared to lowlanders at SL, highlanders exhibited elevated basal plasma and red blood cell NO bioavailability, improved anterior and posterior dCA, elevated anterior CVRCO2 and preserved cerebral substrate delivery, NVC and cognition. In highlanders, S100B, neurofilament light-chain (NF-L) and T-tau were consistently lower and cognition comparable to lowlanders following chronic-HA. These findings highlight novel integrated adaptations towards regulation of the NVU in highlanders that may represent a neuroprotective phenotype underpinning successful adaptation to the lifelong stress of HA hypoxia. KEY POINTS: High-altitude (HA) hypoxia has the potential to alter the structural-functional integrity of the neurovascular unit (NVU) in humans. For the first time, we examined to what extent chronic and lifelong hypoxia impacts multimodal biomarkers reflecting NVU structure and function in lowlanders and native Andean highlanders. Despite lowlanders presenting with a reduction in systemic oxidative-nitrosative stress and maintained cerebral bioenergetics and cerebrovascular function during chronic hypoxia, there was evidence for increased axonal injury and cognitive impairment. Compared to lowlanders at sea level, highlanders exhibited elevated vascular NO bioavailability, improved dynamic regulatory capacity and cerebrovascular reactivity, comparable cerebral substrate delivery and neurovascular coupling, and maintained cognition. Unlike lowlanders following chronic HA, highlanders presented with lower concentrations of S100B, neurofilament light chain and total tau. These findings highlight novel integrated adaptations towards the regulation of the NVU in highlanders that may represent a neuroprotective phenotype underpinning successful adaptation to the lifelong stress of HA hypoxia.
Collapse
Affiliation(s)
- Benjamin S. Stacey
- Neurovascular Research Laboratory, Faculty of Life Sciences and EducationUniversity of South WalesPontypriddUK
| | - Ryan L. Hoiland
- Department of Anaesthesiology, Pharmacology and Therapeutics, Vancouver General HospitalUniversity of British ColumbiaVancouverBritish ColumbiaCanada
- Department of Cellular and Physiological Sciences, Faculty of MedicineUniversity of British ColumbiaVancouverBritish ColumbiaCanada
| | - Hannah G. Caldwell
- Centre for Heart, Lung and Vascular HealthUniversity of British Columbia‐Okanagan CampusKelownaBritish ColumbiaCanada
| | - Connor A. Howe
- Centre for Heart, Lung and Vascular HealthUniversity of British Columbia‐Okanagan CampusKelownaBritish ColumbiaCanada
| | - Tyler Vermeulen
- Centre for Heart, Lung and Vascular HealthUniversity of British Columbia‐Okanagan CampusKelownaBritish ColumbiaCanada
| | - Michael M. Tymko
- Centre for Heart, Lung and Vascular HealthUniversity of British Columbia‐Okanagan CampusKelownaBritish ColumbiaCanada
- Faculty of Kinesiology, Sport, and RecreationUniversity of AlbertaEdmontonAlbertaCanada
- Department of Medicine, Faculty of MedicineUniversity of British ColumbiaVancouverBritish ColumbiaCanada
| | - Gustavo A. Vizcardo‐Galindo
- Laboratorio de Fisiología Comparada, Departamento de Ciencias Biológicas y Fisiológicas, Facultad de Ciencias y FilosofíaUniversidad Peruana Cayetano HerediaLima 31Peru
| | - Daniella Bermudez
- Laboratorio de Fisiología Comparada, Departamento de Ciencias Biológicas y Fisiológicas, Facultad de Ciencias y FilosofíaUniversidad Peruana Cayetano HerediaLima 31Peru
| | - Rómulo J. Figueroa‐Mujíica
- Laboratorio de Fisiología Comparada, Departamento de Ciencias Biológicas y Fisiológicas, Facultad de Ciencias y FilosofíaUniversidad Peruana Cayetano HerediaLima 31Peru
| | - Christopher Gasho
- Division of Pulmonary and Critical CareLoma Linda University School of MedicineLoma LindaCAUSA
| | - Edouard Tuaillon
- Department of Infectious DiseasesUniversity of MontpellierMontpellierFrance
| | - Christophe Hirtz
- LBPC‐PPCUniversité de Montpellier, IRMB CHU de Montpellier, INM INSERMMontpellierFrance
| | - Sylvain Lehmann
- LBPC‐PPCUniversité de Montpellier, IRMB CHU de Montpellier, INM INSERMMontpellierFrance
| | - Nicola Marchi
- Laboratory of Cerebrovascular and Glia Research, Department of Neuroscience, Institute of Functional GenomicsUniversity of MontpellierMontpellierFrance
| | - Hayato Tsukamoto
- Faculty of Sport and Health ScienceRitsumeikan UniversityKusatsuShigaJapan
| | - Francisco C. Villafuerte
- Laboratorio de Fisiología Comparada, Departamento de Ciencias Biológicas y Fisiológicas, Facultad de Ciencias y FilosofíaUniversidad Peruana Cayetano HerediaLima 31Peru
| | - Philip N. Ainslie
- Neurovascular Research Laboratory, Faculty of Life Sciences and EducationUniversity of South WalesPontypriddUK
- Centre for Heart, Lung and Vascular HealthUniversity of British Columbia‐Okanagan CampusKelownaBritish ColumbiaCanada
| | - Damian M. Bailey
- Neurovascular Research Laboratory, Faculty of Life Sciences and EducationUniversity of South WalesPontypriddUK
| |
Collapse
|
14
|
Vizcardo-Galindo GA, Howe CA, Hoiland RL, Carter HH, Willie CK, Ainslie PN, Tremblay JC. Impact of Oxygen Supplementation on Brachial Artery Hemodynamics and Vascular Function During Ascent to 5,050 m. High Alt Med Biol 2023; 24:27-36. [PMID: 36940101 DOI: 10.1089/ham.2022.0107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/21/2023] Open
Abstract
Vizcardo-Galindo, Gustavo A., Connor A. Howe, Ryan L. Hoiland, Howard H. Carter, Christopher K. Willie, Philip N. Ainslie, and Joshua C. Tremblay. Impact of oxygen supplementation on brachial artery hemodynamics and vascular function during ascent to 5,050 m. High Alt Med Biol. 24:27-36, 2023.-High-altitude trekking alters upper limb hemodynamics and reduces brachial artery vascular function in lowlanders. Whether these changes are reversible with the removal of hypoxia is unknown. We investigated the impact of 20 minutes of oxygen supplementation (O2) on brachial artery hemodynamics, reactive hyperemia (RH; microvascular function), and flow-mediated dilation (FMD; endothelial function). Participants (aged 21-42 years) were examined before and with O2 at 3,440 m (n = 7), 4,371 m (n = 7), and 5,050 m (n = 12) using Duplex ultrasound (days 4, 7, and 10 respectively). At 3,440 m, O2 decreased brachial artery diameter (-5% ± 5%; p = 0.04), baseline blood flow (-44% ± 15%; p < 0.001), oxygen delivery (-39 ± 16; p < 0.001), and peak RH (-8% ± 8%; p = 0.02), but not RH normalized for baseline blood flow. Elevated FMD (p = 0.04) with O2 at 3,440 m was attributed to the reduction in baseline diameter. At 5,050 m, a reduction in brachial artery blood flow (-17% ± 22%; p = 0.03), but not oxygen delivery, diameter, RH, or FMD occurred with O2. These findings suggest that during early trekking at high altitude, O2 causes vasoconstriction in the upper limb along the arterial tree (conduit and resistance arteries). With incremental high-altitude exposure, O2 reduces blood flow without compromising oxygen delivery, RH, or FMD, suggesting a differential impact on vascular function modulated by the duration and severity of high-altitude exposure.
Collapse
Affiliation(s)
- Gustavo A Vizcardo-Galindo
- Centre for Heart, Lung & Vascular Health, Faculty of Health and Social Development, University of British Columbia-Okanagan, Kelowna, Canada
| | - Connor A Howe
- Centre for Heart, Lung & Vascular Health, Faculty of Health and Social Development, University of British Columbia-Okanagan, Kelowna, Canada
| | - Ryan L Hoiland
- Centre for Heart, Lung & Vascular Health, Faculty of Health and Social Development, University of British Columbia-Okanagan, Kelowna, Canada
- Department of Anesthesiology, Pharmacology and Therapeutics, Vancouver General Hospital, University of British Columbia, Vancouver, Canada
- Department of Cellular and Physiological Sciences, Faculty of Medicine, University of British Columbia, Vancouver, Canada
- International Collaboration on Repair Discoveries, Vancouver, Canada
| | - Howard H Carter
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
- Cardiovascular Research Group, School of Human Sciences (Exercise and Sport Science), University of Western Australia, Perth, Australia
| | - Christopher K Willie
- Centre for Heart, Lung & Vascular Health, Faculty of Health and Social Development, University of British Columbia-Okanagan, Kelowna, Canada
| | - Philip N Ainslie
- Centre for Heart, Lung & Vascular Health, Faculty of Health and Social Development, University of British Columbia-Okanagan, Kelowna, Canada
| | - Joshua C Tremblay
- Centre for Heart, Lung & Vascular Health, Faculty of Health and Social Development, University of British Columbia-Okanagan, Kelowna, Canada
| |
Collapse
|
15
|
Samaja M, Ottolenghi S. The Oxygen Cascade from Atmosphere to Mitochondria as a Tool to Understand the (Mal)adaptation to Hypoxia. Int J Mol Sci 2023; 24:ijms24043670. [PMID: 36835089 PMCID: PMC9960749 DOI: 10.3390/ijms24043670] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 02/05/2023] [Accepted: 02/09/2023] [Indexed: 02/15/2023] Open
Abstract
Hypoxia is a life-threatening challenge for about 1% of the world population, as well as a contributor to high morbidity and mortality scores in patients affected by various cardiopulmonary, hematological, and circulatory diseases. However, the adaptation to hypoxia represents a failure for a relevant portion of the cases as the pathways of potential adaptation often conflict with well-being and generate diseases that in certain areas of the world still afflict up to one-third of the populations living at altitude. To help understand the mechanisms of adaptation and maladaptation, this review examines the various steps of the oxygen cascade from the atmosphere to the mitochondria distinguishing the patterns related to physiological (i.e., due to altitude) and pathological (i.e., due to a pre-existing disease) hypoxia. The aim is to assess the ability of humans to adapt to hypoxia in a multidisciplinary approach that correlates the function of genes, molecules, and cells with the physiologic and pathological outcomes. We conclude that, in most cases, it is not hypoxia by itself that generates diseases, but rather the attempts to adapt to the hypoxia condition. This underlies the paradigm shift that when adaptation to hypoxia becomes excessive, it translates into maladaptation.
Collapse
Affiliation(s)
- Michele Samaja
- MAGI GROUP, San Felice del Benaco, 25010 Brescia, Italy
- Correspondence:
| | - Sara Ottolenghi
- School of Medicine and Surgery, University of Milano Bicocca, 20126 Milan, Italy
| |
Collapse
|
16
|
DeMartino AW, Poudel L, Dent MR, Chen X, Xu Q, Gladwin BS, Tejero J, Basu S, Alipour E, Jiang Y, Rose JJ, Gladwin MT, Kim-Shapiro DB. Thiol catalyzed formation of NO-ferroheme regulates canonical intravascular NO signaling. RESEARCH SQUARE 2023:rs.3.rs-2402224. [PMID: 36711928 PMCID: PMC9882697 DOI: 10.21203/rs.3.rs-2402224/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Nitric oxide (NO) is an endogenously produced physiological signaling molecule that regulates blood flow and platelet activation. However, both the intracellular and intravascular diffusion of NO is severely limited by scavenging reactions with hemoglobin, myoglobin, and other hemoproteins, raising unanswered questions as to how free NO can signal in hemoprotein-rich environments, like blood and cardiomyocytes. We explored the hypothesis that NO could be stabilized as a ferrous heme-nitrosyl complex (Fe 2+ -NO, NO-ferroheme) either in solution within membranes or bound to albumin. Unexpectedly, we observed a rapid reaction of NO with free ferric heme (Fe 3+ ) and a reduced thiol under physiological conditions to yield NO-ferroheme and a thiyl radical. This thiol-catalyzed reductive nitrosylation reaction occurs readily when the hemin is solubilized in lipophilic environments, such as red blood cell membranes, or bound to serum albumin. NO-ferroheme albumin is stable, even in the presence of excess oxyhemoglobin, and potently inhibits platelet activation. NO-ferroheme-albumin administered intravenously to mice dose-dependently vasodilates at low- to mid-nanomolar concentrations. In conclusion, we report the fastest rate of reductive nitrosylation observed to date to generate a NO-ferroheme molecule that resists oxidative inactivation, is soluble in cell membranes, and is transported intravascularly by albumin to promote potent vasodilation.
Collapse
Affiliation(s)
- Anthony W. DeMartino
- Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Laxman Poudel
- Department of Physics, Wake Forest University, Winston-Salem, NC 27109, USA
| | - Matthew R. Dent
- Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Xiukai Chen
- Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Qinzi Xu
- Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Brendan S. Gladwin
- Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Jesús Tejero
- Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA 15261, USA
- Division of Pulmonary, Allergy and Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15260, USA
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA
| | - Swati Basu
- Department of Physics, Wake Forest University, Winston-Salem, NC 27109, USA
- Translational Science Center, Wake Forest University, Winston-Salem, NC 27109, USA
| | - Elmira Alipour
- Department of Physics, Wake Forest University, Winston-Salem, NC 27109, USA
| | - Yiyang Jiang
- Department of Physics, Wake Forest University, Winston-Salem, NC 27109, USA
| | - Jason J. Rose
- Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Mark T. Gladwin
- Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Daniel B. Kim-Shapiro
- Department of Physics, Wake Forest University, Winston-Salem, NC 27109, USA
- Translational Science Center, Wake Forest University, Winston-Salem, NC 27109, USA
| |
Collapse
|
17
|
Mallet RT, Burtscher J, Pialoux V, Pasha Q, Ahmad Y, Millet GP, Burtscher M. Molecular Mechanisms of High-Altitude Acclimatization. Int J Mol Sci 2023; 24:ijms24021698. [PMID: 36675214 PMCID: PMC9866500 DOI: 10.3390/ijms24021698] [Citation(s) in RCA: 28] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 01/11/2023] [Accepted: 01/13/2023] [Indexed: 01/17/2023] Open
Abstract
High-altitude illnesses (HAIs) result from acute exposure to high altitude/hypoxia. Numerous molecular mechanisms affect appropriate acclimatization to hypobaric and/or normobaric hypoxia and curtail the development of HAIs. The understanding of these mechanisms is essential to optimize hypoxic acclimatization for efficient prophylaxis and treatment of HAIs. This review aims to link outcomes of molecular mechanisms to either adverse effects of acute high-altitude/hypoxia exposure or the developing tolerance with acclimatization. After summarizing systemic physiological responses to acute high-altitude exposure, the associated acclimatization, and the epidemiology and pathophysiology of various HAIs, the article focuses on molecular adjustments and maladjustments during acute exposure and acclimatization to high altitude/hypoxia. Pivotal modifying mechanisms include molecular responses orchestrated by transcription factors, most notably hypoxia inducible factors, and reciprocal effects on mitochondrial functions and REDOX homeostasis. In addition, discussed are genetic factors and the resultant proteomic profiles determining these hypoxia-modifying mechanisms culminating in successful high-altitude acclimatization. Lastly, the article discusses practical considerations related to the molecular aspects of acclimatization and altitude training strategies.
Collapse
Affiliation(s)
- Robert T. Mallet
- Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, TX 76107, USA
| | - Johannes Burtscher
- Department of Biomedical Sciences, University of Lausanne, CH-1005 Lausanne, Switzerland
- Institute of Sport Sciences, University of Lausanne, CH-1005 Lausanne, Switzerland
| | - Vincent Pialoux
- Inter-University Laboratory of Human Movement Biology EA7424, University Claude Bernard Lyon 1, University of Lyon, FR-69008 Lyon, France
| | - Qadar Pasha
- Institute of Hypoxia Research, New Delhi 110067, India
| | - Yasmin Ahmad
- Defense Institute of Physiology & Allied Sciences (DIPAS), Defense Research & Development Organization(DRDO), New Delhi 110054, India
| | - Grégoire P. Millet
- Department of Biomedical Sciences, University of Lausanne, CH-1005 Lausanne, Switzerland
- Institute of Sport Sciences, University of Lausanne, CH-1005 Lausanne, Switzerland
| | - Martin Burtscher
- Department of Sport Science, University of Innsbruck, A-6020 Innsbruck, Austria
- Austrian Society for Alpine and High-Altitude Medicine, A-6020 Innsbruck, Austria
- Correspondence:
| |
Collapse
|
18
|
Moraitou M, Forsythe A, Fellows Yates JA, Brealey JC, Warinner C, Guschanski K. Ecology, Not Host Phylogeny, Shapes the Oral Microbiome in Closely Related Species. Mol Biol Evol 2022; 39:6874787. [PMID: 36472532 PMCID: PMC9778846 DOI: 10.1093/molbev/msac263] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 11/25/2022] [Accepted: 12/01/2022] [Indexed: 12/12/2022] Open
Abstract
Host-associated microbiomes are essential for a multitude of biological processes. Placed at the contact zone between external and internal environments, the little-studied oral microbiome has important roles in host physiology and health. Here, we investigate the roles of host evolutionary relationships and ecology in shaping the oral microbiome in three closely related gorilla subspecies (mountain, Grauer's, and western lowland gorillas) using shotgun metagenomics of 46 museum-preserved dental calculus samples. We find that the oral microbiomes of mountain gorillas are functionally and taxonomically distinct from the other two subspecies, despite close evolutionary relationships and geographic proximity with Grauer's gorillas. Grauer's gorillas show intermediate bacterial taxonomic and functional, and dietary profiles. Altitudinal differences in gorilla subspecies ranges appear to explain these patterns, suggesting a close connection between dental calculus microbiomes and the environment, likely mediated through diet. This is further supported by the presence of gorilla subspecies-specific phyllosphere/rhizosphere taxa in the oral microbiome. Mountain gorillas show a high abundance of nitrate-reducing oral taxa, which may promote adaptation to a high-altitude lifestyle by modulating blood pressure. Our results suggest that ecology, rather than evolutionary relationships and geographic distribution, shape the oral microbiome in these closely related species.
Collapse
Affiliation(s)
| | | | - James A Fellows Yates
- Department of Archaeogenetics, Max Planck Institute for Evolutionary Anthropology, 04103 Leipzig, Germany,Department of Paleobiotechnology, Leibniz Institute for Natural Product Research and Infection Biology Hans Knöll Institute, 07745 Jena, Germany
| | - Jaelle C Brealey
- Department of Natural History, NTNU University Museum, Norwegian University of Science and Technology, 7491 Trondheim, Norway
| | - Christina Warinner
- Department of Archaeogenetics, Max Planck Institute for Evolutionary Anthropology, 04103 Leipzig, Germany,Department of Paleobiotechnology, Leibniz Institute for Natural Product Research and Infection Biology Hans Knöll Institute, 07745 Jena, Germany,Faculty of Biological Sciences, Friedrich Schiller University, 07743 Jena, Germany,Department of Anthropology, Harvard University, Cambridge, MA 02138, USA
| | | |
Collapse
|
19
|
Chronic High-Altitude Hypoxia Alters Iron and Nitric Oxide Homeostasis in Fetal and Maternal Sheep Blood and Aorta. Antioxidants (Basel) 2022; 11:antiox11091821. [PMID: 36139895 PMCID: PMC9495375 DOI: 10.3390/antiox11091821] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 09/09/2022] [Accepted: 09/12/2022] [Indexed: 11/16/2022] Open
Abstract
The mammalian fetus thrives at oxygen tensions much lower than those of adults. Gestation at high altitude superimposes hypoxic stresses on the fetus resulting in increased erythropoiesis. We hypothesized that chronic hypoxia at high altitude alters the homeostasis of iron and bioactive nitric oxide metabolites (NOx) in gestation. To test for this, electron paramagnetic resonance was used to provide unique measurements of iron, metalloproteins, and free radicals in the blood and aorta of fetal and maternal sheep from either high or low altitudes (3801 or 300 m). Using ozone-based chemiluminescence with selectivity for various NOx species, we determined the NOx levels in these samples immediately after collection. These experiments demonstrated a systemic redistribution of iron in high altitude fetuses as manifested by a decrease in both chelatable and total iron in the aorta and an increase in non-transferrin bound iron and total iron in plasma. Likewise, high altitude altered the redox status diversely in fetal blood and aorta. This study also found significant increases in blood and aortic tissue NOx in fetuses and mothers at high altitude. In addition, gradients in NOx concentrations observed between fetus and mother, umbilical artery and vein, and plasma and RBCs demonstrated complex dynamic homeostasis of NOx among these circulatory compartments, such as placental generation and efflux as well as fetal consumption of iron-nitrosyls in RBCs, probably HbNO. In conclusion, these results may suggest the utilization of iron from non-hematopoietic tissues iron for erythropoiesis in the fetus and increased NO bioavailability in response to chronic hypoxic stress at high altitude during gestation.
Collapse
|
20
|
Yu JJ, Non AL, Heinrich EC, Gu W, Alcock J, Moya EA, Lawrence ES, Tift MS, O'Brien KA, Storz JF, Signore AV, Khudyakov JI, Milsom WK, Wilson SM, Beall CM, Villafuerte FC, Stobdan T, Julian CG, Moore LG, Fuster MM, Stokes JA, Milner R, West JB, Zhang J, Shyy JY, Childebayeva A, Vázquez-Medina JP, Pham LV, Mesarwi OA, Hall JE, Cheviron ZA, Sieker J, Blood AB, Yuan JX, Scott GR, Rana BK, Ponganis PJ, Malhotra A, Powell FL, Simonson TS. Time Domains of Hypoxia Responses and -Omics Insights. Front Physiol 2022; 13:885295. [PMID: 36035495 PMCID: PMC9400701 DOI: 10.3389/fphys.2022.885295] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Accepted: 05/24/2022] [Indexed: 02/04/2023] Open
Abstract
The ability to respond rapidly to changes in oxygen tension is critical for many forms of life. Challenges to oxygen homeostasis, specifically in the contexts of evolutionary biology and biomedicine, provide important insights into mechanisms of hypoxia adaptation and tolerance. Here we synthesize findings across varying time domains of hypoxia in terms of oxygen delivery, ranging from early animal to modern human evolution and examine the potential impacts of environmental and clinical challenges through emerging multi-omics approaches. We discuss how diverse animal species have adapted to hypoxic environments, how humans vary in their responses to hypoxia (i.e., in the context of high-altitude exposure, cardiopulmonary disease, and sleep apnea), and how findings from each of these fields inform the other and lead to promising new directions in basic and clinical hypoxia research.
Collapse
Affiliation(s)
- James J. Yu
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA, United States
| | - Amy L. Non
- Department of Anthropology, Division of Social Sciences, University of California, San Diego, La Jolla, CA, United States,*Correspondence: Amy L. Non, Tatum S. Simonson,
| | - Erica C. Heinrich
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA, United States
| | - Wanjun Gu
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA, United States,Herbert Wertheim School of Public Health and Longevity Sciences, University of California, San Diego, La Jolla, CA, United States
| | - Joe Alcock
- Department of Emergency Medicine, University of New Mexico, Albuquerque, MX, United States
| | - Esteban A. Moya
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA, United States
| | - Elijah S. Lawrence
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA, United States
| | - Michael S. Tift
- Department of Biology and Marine Biology, College of Arts and Sciences, University of North Carolina Wilmington, Wilmington, NC, United States
| | - Katie A. O'Brien
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA, United States,Department of Physiology, Development and Neuroscience, Faculty of Biology, School of Biological Sciences, University of Cambridge, Cambridge, ENG, United Kingdom
| | - Jay F. Storz
- School of Biological Sciences, College of Arts and Sciences, University of Nebraska-Lincoln, Lincoln, IL, United States
| | - Anthony V. Signore
- School of Biological Sciences, College of Arts and Sciences, University of Nebraska-Lincoln, Lincoln, IL, United States
| | - Jane I. Khudyakov
- Department of Biological Sciences, University of the Pacific, Stockton, CA, United States
| | | | - Sean M. Wilson
- Lawrence D. Longo, MD Center for Perinatal Biology, Loma Linda, CA, United States
| | | | | | | | - Colleen G. Julian
- School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Lorna G. Moore
- Division of Reproductive Sciences, Department of Obstetrics and Gynecology, Aurora, CO, United States
| | - Mark M. Fuster
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA, United States
| | - Jennifer A. Stokes
- Department of Kinesiology, Southwestern University, Georgetown, TX, United States
| | - Richard Milner
- San Diego Biomedical Research Institute, San Diego, CA, United States
| | - John B. West
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA, United States
| | - Jiao Zhang
- Department of Medicine, UC San Diego School of Medicine, San Diego, CA, United States
| | - John Y. Shyy
- Department of Medicine, UC San Diego School of Medicine, San Diego, CA, United States
| | - Ainash Childebayeva
- Department of Archaeogenetics, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - José Pablo Vázquez-Medina
- Department of Integrative Biology, College of Letters and Science, University of California, Berkeley, Berkeley, CA, United States
| | - Luu V. Pham
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, School of Medicine, Johns Hopkins Medicine, Baltimore, MD, United States
| | - Omar A. Mesarwi
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA, United States
| | - James E. Hall
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA, United States
| | - Zachary A. Cheviron
- Division of Biological Sciences, College of Humanities and Sciences, University of Montana, Missoula, MT, United States
| | - Jeremy Sieker
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA, United States
| | - Arlin B. Blood
- Department of Pediatrics Division of Neonatology, School of Medicine, Loma Linda University, Loma Linda, CA, United States
| | - Jason X. Yuan
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA, United States
| | - Graham R. Scott
- Department of Pediatrics Division of Neonatology, School of Medicine, Loma Linda University, Loma Linda, CA, United States
| | - Brinda K. Rana
- Moores Cancer Center, UC San Diego, La Jolla, CA, United States,Department of Psychiatry, UC San Diego, La Jolla, CA, United States
| | - Paul J. Ponganis
- Center for Marine Biotechnology and Biomedicine, La Jolla, CA, United States
| | - Atul Malhotra
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA, United States
| | - Frank L. Powell
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA, United States
| | - Tatum S. Simonson
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA, United States,*Correspondence: Amy L. Non, Tatum S. Simonson,
| |
Collapse
|
21
|
Williams AM, Levine BD, Stembridge M. A change of heart: mechanisms of cardiac adaptation to acute and chronic hypoxia. J Physiol 2022; 600:4089-4104. [PMID: 35930370 PMCID: PMC9544656 DOI: 10.1113/jp281724] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 07/21/2022] [Indexed: 11/20/2022] Open
Abstract
Over the last 100 years, high‐altitude researchers have amassed a comprehensive understanding of the global cardiac responses to acute, prolonged and lifelong hypoxia. When lowlanders are exposed to hypoxia, the drop in arterial oxygen content demands an increase in cardiac output, which is facilitated by an elevated heart rate at the same time as ventricular volumes are maintained. As exposure is prolonged, haemoconcentration restores arterial oxygen content, whereas left ventricular filling and stroke volume are lowered as a result of a combination of reduced blood volume and hypoxic pulmonary vasoconstriction. Populations native to high‐altitude, such as the Sherpa in Asia, exhibit unique lifelong or generational adaptations to hypoxia. For example, they have smaller left ventricular volumes compared to lowlanders despite having larger total blood volume. More recent investigations have begun to explore the mechanisms underlying such adaptive responses by combining novel imaging techniques with interventions that manipulate cardiac preload, afterload, and/or contractility. This work has revealed the contributions and interactions of (i) plasma volume constriction; (ii) sympathoexcitation; and (iii) hypoxic pulmonary vasoconstriction with respect to altering cardiac loading, or otherwise preserving or enhancing biventricular systolic and diastolic function even amongst high altitude natives with excessive erythrocytosis. Despite these advances, various areas of investigation remain understudied, including potential sex‐related differences in response to high altitude. Collectively, the available evidence supports the conclusion that the human heart successfully adapts to hypoxia over the short‐ and long‐term, without signs of myocardial dysfunction in healthy humans, except in very rare cases of maladaptation.
![]()
Collapse
Affiliation(s)
- Alexandra M Williams
- Department of Cellular and Physiological Sciences, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada.,International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, BC, Canada
| | - Benjamin D Levine
- Institute for Exercise and Environmental Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Mike Stembridge
- Cardiff School of Sport and Health Sciences, Cardiff Metropolitan University, Cardiff, UK
| |
Collapse
|
22
|
DE Souza DB, Ribeiro JN, Simão ANC, Aguilar-Navarro M, Polito MD. The Acute Effect of In Natura Beetroot Juice Intake on Intra-Session Exercise Sequences During Concurrent Training. INTERNATIONAL JOURNAL OF EXERCISE SCIENCE 2022; 15:1075-1085. [PMID: 36159160 PMCID: PMC9458277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
The purpose of this study was to analyze the acute effects of in natura beetroot juice intake on intra-session exercise sequences during concurrent training. Following a randomized double-blind placebo-controlled crossover design, 20 well-trained men (21.4 ± 2.9 years; 74.8 ± 6.3 kg; 175.7 ± 5.0 cm) performed two concurrent training sessions with different intra-session exercise sequences: CT1 (aerobic exercise + resistance exercises) and CT2 (resistance exercises + aerobic exercise). The resistance exercises were bench-press, lat-pull down, and shoulder-press (three sets to failure; 2 s cadence for the concentric and eccentric phases; 90 s rest interval between sets and exercises; 75% 1RM), and the aerobic exercise was 4-km running. Each concurrent training session was randomized to placebo, beetroot juice, and control (no substances), totaling six exercise sessions. The rate of perceived exertion (RPE) was reported at the end of each exercise in each session. The beetroot juice significantly increased plasma nitric oxide concentration from 14.5 ± 3.9 mmol/L to 140.2 ± 37.5 mmol/L (P < 0.01) and there was no significant change after placebo intake (13.8 ± 4.2 vs 15.1 ± 5.7 mmol/L). The 4-km running time was significantly less (P < 0.05) after beetroot juice intake in CT1 (17.0 ± 2.1 min) and CT2 (18.5 ± 1.9 min) than placebo (19.1 ± 3.2 and 22.2 ± 2.9 min, respectively) and control (19.4 ± 2.6 and 21.7 ± 3.0 min, respectively). No differences were identified in the total number of repetitions in resistance exercises and RPE. In conclusion, the acute intake of in natura beetroot juice decreased the 4-km running time independently of concurrent training exercise sequences. Our results may assist trainers in order to choose the supplement to increase performance.
Collapse
Affiliation(s)
| | - Júlio Nobile Ribeiro
- Center of Physical Education and Sport, State University of Londrina, Londrina, Paraná, PR, BRAZIL
| | | | | | - Marcos Doederlein Polito
- Center of Physical Education and Sport, State University of Londrina, Londrina, Paraná, PR, BRAZIL
| |
Collapse
|
23
|
Circulating nitrate-nitrite reduces oxygen uptake for improving resistance exercise performance after rest time in well-trained CrossFit athletes. Sci Rep 2022; 12:9671. [PMID: 35690665 PMCID: PMC9188609 DOI: 10.1038/s41598-022-13786-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 05/27/2022] [Indexed: 12/21/2022] Open
Abstract
This study aimed to determine the effects of circulating nitrate plus nitrite (NOx) concentrations on resistance exercise performance, VO2 and biomarkers of muscle damage. Eleven well-trained male CrossFit athletes (29.2 ± 3.7 years, 78.9 ± 5.4 kg, 175.1 ± 6.3 cm) carried out a resistance exercise test after drinking 140 mL of beetroot juice (BJ) or placebo. The test consisted of repeating the same resistance exercise routine twice: wall ball shots plus full back squat with 3-min rest (1st routine) or without rest (2nd routine) between the two exercises. Higher NOx plasma levels were verified after BJ than placebo in the pretest and post-test (p < 0.001). A higher number of repetitions was observed after BJ intake compared to placebo in the full back squat exercise during the first routine (p = 0.004). A significantly reduced VO2 was detected after BJ intake compared to placebo during rest and full back squat execution in the first routine (p < 0.05). Plasma myoglobin concentrations were significantly increased with BJ compared to placebo (p = 0.036). These results showed that plasma NOx levels reduced VO2 after BJ intake during rest time. These reduced VO2 was a key factor for improving full back squat performance during the first routine.
Collapse
|
24
|
Bian SZ, Zhang C, Rao RS, Ding XH, Huang L. Systemic Blood Predictors of Elevated Pulmonary Artery Pressure Assessed by Non-invasive Echocardiography After Acute Exposure to High Altitude: A Prospective Cohort Study. Front Cardiovasc Med 2022; 9:866093. [PMID: 35757324 PMCID: PMC9226344 DOI: 10.3389/fcvm.2022.866093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Accepted: 05/06/2022] [Indexed: 11/14/2022] Open
Abstract
Aim Elevated pulmonary artery pressure (ePAP) in response to high-altitude hypoxia is a critical physiopathological factor in the hypoxic adaptation that may lead to high-altitude pulmonary edema in the acute phase or high-altitude pulmonary hypertension in the long term. However, the sea-level predictors of risk factors for altitude-induced ePAP have not been examined. Thus, we aimed to identify the baseline systemic blood predictors of ePAP after acute high-altitude exposure. Materials and Methods A total of 154 participants were transported to a high altitude 3,700 m from sea level within 2 h. Echocardiography examinations were performed to assess the mean pulmonary artery pressure (mPAP) and hemodynamics at both altitudes. All the individuals underwent blood tests to determine the concentrations of vascular regulatory factors. Univariate and adjusted logistic regression analyses were performed to identify the independent predictors of ePAP and factors related to ePAP. Results The mPAP increased significantly from sea level to high altitude (19.79 ± 6.53–27.16 ± 7.16 mmHg, p < 0.05). Increased levels of endothelin (ET-1), Ang (1–7), Ang II, and bradykinin were found after high-altitude exposure, while the levels of nitric oxide (NO), prostaglandin E2 (PEG2), and serotonin decreased sharply (all p-values < 0.05). At high altitude, 52.6% of the subjects exhibited ePAP, and the mPAP was closely correlated with the baseline Ang II level (r = 0.170, p = 0.036) and follow-up levels of NO (r = −0.209, p = 0.009), Ang II (r = 0.246, p = 0.002), and Ang (1–7) (r = −0.222, p = 0.006) and the left atrial inner diameter (LAD, r = 0.270, p < 0.001). Both the baseline and follow-up NO and Ang II levels were significantly different between the ePAP and non-ePAP groups. Finally, we identified the baseline Ang II and NO concentrations as two independent predictors of ePAP (p < 0.05). We also found that two vascular regulatory factors with inverse roles, namely, Ang (1–7) and Ang II, at high altitudes were independently associated with ePAP. Additionally, ET-1, NO, PEG2, and LAD were associated with ePAP. Conclusion The baseline concentrations of Ang II and NO at sea level are two independent predictors of ePAP after acute high-altitude exposure. Furthermore, Ang (1-7) and Ang II combined with ET-1, NO, PEG2, and LAD at high altitudes may contribute to the development of ePAP.
Collapse
Affiliation(s)
- Shi-Zhu Bian
- Department of Cardiology, Xinqiao Hospital, Institute of Cardiovascular Diseases, Army Medical University (Third Military Medical University), Chongqing, China
| | - Chen Zhang
- Department of Cardiology, Xinqiao Hospital, Institute of Cardiovascular Diseases, Army Medical University (Third Military Medical University), Chongqing, China
| | - Rong-Sheng Rao
- Department of Ultrasonography, Xinqiao Hospital, Army Medical University (Third Military Medical University), Chongqing, China
| | - Xiao-Han Ding
- Department of Health Care and Geriatrics, The 940th Hospital of Joint Logistics Support of Chinese People’s Liberation Army (PLA), Lanzhou, China
| | - Lan Huang
- Department of Cardiology, Xinqiao Hospital, Institute of Cardiovascular Diseases, Army Medical University (Third Military Medical University), Chongqing, China
- *Correspondence: Lan Huang,
| |
Collapse
|
25
|
Arima H, Koirala S, Nema K, Nakano M, Ito H, Poudel KM, Pandey K, Pandey BD, Yamamoto T. High prevalence of rheumatoid arthritis and its risk factors among Tibetan highlanders living in Tsarang, Mustang district of Nepal. J Physiol Anthropol 2022; 41:12. [PMID: 35366946 PMCID: PMC8976395 DOI: 10.1186/s40101-022-00283-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 03/11/2022] [Indexed: 12/04/2022] Open
Abstract
Background In Tsarang (at 3560 m), which is located in Mustang, 62.7% of the residents answered that they had a subjective medical history of arthritis, and 41.1% of the residents answered that their families had a subjective medical history of arthritis on a survey conducted in 2017. The expression of hypoxia-inducible factor (HIF) and its effects are deeply involved in hypoxic adaptation in Tibetan highlanders. At the same time, HIF is also related to the onset of rheumatoid arthritis. Therefore, the adaptive mechanism acquired by Tibetan highlanders may promote the development of rheumatoid arthritis. The prevalence of rheumatoid arthritis is estimated to be approximately 0.5–1.0% worldwide. The objective of this study was to estimate the prevalence of rheumatoid arthritis in Tsarang residents using existing diagnostic criteria and to explore its risk factors. Methods An epidemiological survey was conducted in Tsarang in 2019. Data obtained from anthropometry and questionnaires were statistically analyzed. Biochemical measurements using blood samples were also performed, and the results were used to assess arthritis status. Residents’ joint status was scored, and arthritis was assessed based on the clinical disease activity index and ACR/EULAR 2010 criteria. Results Twenty-seven males and 50 females participated in this survey. In Tsarang, ACR/EULAR 2010 classified 4.3% of males and 7.1% of females as having rheumatoid arthritis, indicating a very high estimated prevalence. We also performed a multivariate analysis to explore its risk factors, and two factors, older age (standardized parameter estimate = 4.84E−01, 95% CI = [9.19E−02, 8.76E−01], p = 0.0170) and a history of living in urban areas (standardized parameter estimate = − 5.49E−01, 95% CI = [− 9.21E−01, 1.77E−01], p = 0.0050), significantly contributed to the higher ACR/EULAR 2010 score in females. In addition, three factors, having no spouse (standardized parameter estimate = 3.17E−01, 95% CI = [5.74E−02, 5.77E−01], p = 0.0179), having a smoking habit (standardized parameter estimate = 2.88E−01, 95% CI = [1.71E−02, 5.59E−01], p = 0.0377), and a history of living in urban areas (standardized parameter estimate = − 3.69E−01, 95% CI = [− 6.83E−01, − 5.60E−02], p = 0.0219), resulted in significantly higher clinical disease activity index scores in females. Furthermore, smoking habits were found to significantly increase blood hyaluronic acid in both males (standardized parameter estimate = 6.03E−01, 95% CI = [3.06E−01, 9.01E−01], p = 0.0020) and females (standardized parameter estimate = 4.87E−01, 95% CI = [5.63E−02, 9.18E−01], p = 0.0291). Conclusions In this study, we evaluated the symptoms of arthritis and estimated the prevalence of rheumatoid arthritis using classification criteria for Tibetan highlanders who have adapted to the hypoxic environment and fostered their own culture. The high prevalence of rheumatoid arthritis among Tsarang residents suggests that the hypoxic adaptation mechanism involving HIF in Tibetan highlanders may promote the onset or exacerbation of rheumatoid arthritis. The high prevalence of rheumatoid arthritis among Tibetan highlanders may be related not only to the environmental factors analyzed in this study but also to hypoxic adaptation genes. Further investigation is needed to clarify the genetic factors involved.
Collapse
Affiliation(s)
- Hiroaki Arima
- Department of International Health and Medical Anthropology, Institute of Tropical Medicine, Nagasaki University, 1-12-4 Sakamoto, Nagasaki, 852-8523, Japan
| | - Sweta Koirala
- Nepal Development Society, Bharatpur-5, Chitwan, Nepal
| | - Kotaro Nema
- Department of International Health and Medical Anthropology, Institute of Tropical Medicine, Nagasaki University, 1-12-4 Sakamoto, Nagasaki, 852-8523, Japan.,School of Medical Sciences, Nagasaki University, 1-12-4 Sakamoto, Nagasaki, Japan
| | - Masayuki Nakano
- Department of Nutrition, Faculty of Health Sciences, Kochi Gakuen University, 292-26 Asahitenjin-cho, Kochi, Japan
| | - Hiromu Ito
- Department of International Health and Medical Anthropology, Institute of Tropical Medicine, Nagasaki University, 1-12-4 Sakamoto, Nagasaki, 852-8523, Japan
| | - Kapil Madi Poudel
- Institute of Medicine, Tribhuvan University, Maharajgung, 44600, Nepal
| | - Kishor Pandey
- Central Department of Zoology, Tribhuvan University, Kirtipur, Nepal
| | - Basu Dev Pandey
- Department of Molecular Epidemiology, Institute of Tropical Medicine, Nagasaki University, 1-12-4 Sakamoto, Nagasaki, Japan
| | - Taro Yamamoto
- Department of International Health and Medical Anthropology, Institute of Tropical Medicine, Nagasaki University, 1-12-4 Sakamoto, Nagasaki, 852-8523, Japan. .,Graduate School of Biomedical Sciences, Nagasaki University, 1-12-4 Sakamoto, Nagasaki, Japan. .,Leading Program, Graduate School of Biomedical Sciences, Nagasaki University, 1-12-4 Sakamoto, Nagasaki, Japan.
| |
Collapse
|
26
|
Hennis PJ, Cumpstey AF, O'Doherty AF, Fernandez BO, Gilbert-Kawai ET, Mitchell K, Moyses H, Cobb A, Meale P, Pöhnl H, Mythen MG, Grocott MPW, Levett DZH, Martin DS, Feelisch M. Dietary Nitrate Supplementation Does Not Alter Exercise Efficiency at High Altitude - Further Results From the Xtreme Alps Study. Front Physiol 2022; 13:827235. [PMID: 35295581 PMCID: PMC8918982 DOI: 10.3389/fphys.2022.827235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Accepted: 01/18/2022] [Indexed: 11/13/2022] Open
Abstract
Introduction Nitrate supplementation in the form of beetroot juice (BRJ) ingestion has been shown to improve exercise tolerance during acute hypoxia, but its effect on exercise physiology remains unstudied during sustained terrestrial high altitude exposure. We hypothesized that performing exercise at high altitude would lower circulating nitrate and nitrite levels and that BRJ ingestion would reverse this phenomenon while concomitantly improving key determinants of aerobic exercise performance. Methods Twenty seven healthy volunteers (21 male) underwent a series of exercise tests at sea level (SL, London, 75 m) and again after 5-8 days at high altitude (HA, Capanna Regina Margherita or "Margherita Hut," 4,559 m). Using a double-blind protocol, participants were randomized to consume a beetroot/fruit juice beverage (three doses per day) with high levels of nitrate (∼0.18 mmol/kg/day) or a nitrate-depleted placebo (∼11.5 μmoles/kg/day) control drink, from 3 days prior to the exercise trials until completion. Submaximal constant work rate cycle tests were performed to determine exercise efficiency and a maximal incremental ramp exercise test was undertaken to measure aerobic capacity, using breath-by-breath pulmonary gas exchange measurements throughout. Concentrations of nitrate, nitrite and nitrosation products were quantified in plasma samples collected at 5 timepoints during the constant work rate tests. Linear mixed modeling was used to analyze data. Results At both SL and HA, plasma nitrate concentrations were elevated in the nitrate supplementation group compared to placebo (P < 0.001) but did not change throughout increasing exercise work rate. Delta exercise efficiency was not altered by altitude exposure (P = 0.072) or nitrate supplementation (P = 0.836). V̇O2peak decreased by 24% at high altitude (P < 0.001) and was lower in the nitrate-supplemented group at both sea level and high altitude compared to placebo (P = 0.041). Dietary nitrate supplementation did not alter other peak exercise variables or oxygen consumption at anaerobic threshold. Circulating nitrite and S-nitrosothiol levels unexpectedly rose in a few individuals right after cessation of exercise at high altitude. Conclusion Whilst regularly consumed during an 8 days expedition to terrestrial high altitude, nitrate supplementation did not alter exercise efficiency and other exercise physiological variables, except decreasing V̇O2peak. These results and those of others question the practical utility of BRJ consumption during prolonged altitude exposure.
Collapse
Affiliation(s)
- Philip J Hennis
- Centre for Altitude Space and Extreme Environment Medicine, University College London Hospital NIHR Biomedical Research Centre, Institute of Sport, Exercise and Health, London, United Kingdom.,SHAPE Research Group, School of Science and Technology, Nottingham Trent University, Nottingham, United Kingdom
| | - Andrew F Cumpstey
- Perioperative and Critical Care Theme, NIHR Southampton Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom.,Integrative Physiology and Critical Illness Group, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - Alasdair F O'Doherty
- Department of Sport, Exercise and Rehabilitation, Northumbria University, Newcastle upon Tyne, United Kingdom
| | - Bernadette O Fernandez
- Integrative Physiology and Critical Illness Group, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom.,Division of Metabolic and Vascular Health, Warwick Medical School, University of Warwick, Coventry, United Kingdom
| | - Edward T Gilbert-Kawai
- Centre for Altitude Space and Extreme Environment Medicine, University College London Hospital NIHR Biomedical Research Centre, Institute of Sport, Exercise and Health, London, United Kingdom
| | - Kay Mitchell
- Perioperative and Critical Care Theme, NIHR Southampton Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom.,Integrative Physiology and Critical Illness Group, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - Helen Moyses
- Perioperative and Critical Care Theme, NIHR Southampton Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom
| | - Alexandra Cobb
- Centre for Altitude Space and Extreme Environment Medicine, University College London Hospital NIHR Biomedical Research Centre, Institute of Sport, Exercise and Health, London, United Kingdom
| | - Paula Meale
- Centre for Altitude Space and Extreme Environment Medicine, University College London Hospital NIHR Biomedical Research Centre, Institute of Sport, Exercise and Health, London, United Kingdom
| | - Helmut Pöhnl
- AURAPA Würzungen GmbH, Bietigheim-Bissingen, Germany
| | - Monty G Mythen
- Centre for Altitude Space and Extreme Environment Medicine, University College London Hospital NIHR Biomedical Research Centre, Institute of Sport, Exercise and Health, London, United Kingdom
| | - Michael P W Grocott
- Perioperative and Critical Care Theme, NIHR Southampton Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom.,Integrative Physiology and Critical Illness Group, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - Denny Z H Levett
- Perioperative and Critical Care Theme, NIHR Southampton Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom.,Integrative Physiology and Critical Illness Group, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - Daniel S Martin
- Centre for Altitude Space and Extreme Environment Medicine, University College London Hospital NIHR Biomedical Research Centre, Institute of Sport, Exercise and Health, London, United Kingdom.,Peninsula Medical School, University of Plymouth, Plymouth, United Kingdom
| | - Martin Feelisch
- Perioperative and Critical Care Theme, NIHR Southampton Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom.,Integrative Physiology and Critical Illness Group, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom.,Division of Metabolic and Vascular Health, Warwick Medical School, University of Warwick, Coventry, United Kingdom
| | | |
Collapse
|
27
|
Xin Y, Yang Z, Zhu Y, Li Y, Yu J, Zhong W, Chen Y, Lv X, Hu J, Lin J, Miao Y, Wang L. Hypoxia Induces Oxidative Injury and Apoptosis via Mediating the Nrf-2/Hippo Pathway in Blood Cells of Largemouth Bass (Micropterus salmoides). Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.841318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Investigating how aquatic animals respond to hypoxia brought about by changes in environmental temperature may be of great significance to avoid oxidative injury and maintain the quality of farmed fish in the background of global warming. Here, we investigated the effects of hypoxia on oxidative injury and environment-sensing pathway in blood cells of Micropterus salmoides. The total blood cell count (TBCC) and Giemsa staining showed that hypoxia could lead to damage of blood cells. Flow cytometry analysis confirmed that the apoptosis rate, Ca2+ level, NO production and ROS of blood cells were significantly increased under hypoxia stress. Environment-sensing pathways, such as Nrf2 pathway showed that hypoxia resulted in significant up-regulation of hiF-1 alpha subunit (Hif-1α), nuclear factor erythroid 2-related factor 2 (Nrf2) and kelch-1ike ECH- associated protein l (Keap1) expression. Meanwhile, the expression of Hippo pathway-related genes such as MOB kinase activator 1 (MOB1), large tumor suppressor homolog 1/2 (Lats1/2), yes-associated protein/transcriptional co-activator with PDZ-binding motif (YAP/TAZ), protein phosphatase 2A (PP2A) were significantly increased in blood cells after hypoxia exposure. In addition, hypoxia stress also increased the expression of catalase (CAT) and glutathione peroxidase (GPx), but decreased the expression of superoxide dismutase (SOD). Consequently, our results suggested that hypoxia could induce oxidative injury and apoptosis via mediating environment-sensing pathway such as Nrf2/Hippo pathway in blood cells of M. salmoides.
Collapse
|
28
|
Cas MD, Morano C, Ottolenghi S, Dicasillati R, Roda G, Samaja M, Paroni R. Inside the Alterations of Circulating Metabolome in Antarctica: The Adaptation to Chronic Hypoxia. Front Physiol 2022; 13:819345. [PMID: 35145434 PMCID: PMC8821919 DOI: 10.3389/fphys.2022.819345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2021] [Accepted: 01/04/2022] [Indexed: 11/21/2022] Open
Abstract
Although the human body may dynamically adapt to mild and brief oxygen shortages, there is a growing interest in understanding how the metabolic pathways are modified during sustained exposure to chronic hypoxia. Located at an equivalent altitude of approximately 3,800 m asl, the Concordia Station in Antarctica represents an opportunity to study the course of human adaption to mild hypoxia with reduced impact of potentially disturbing variables else than oxygen deprivation. We recruited seven healthy subjects who spent 10 months in the Concordia Station, and collected plasma samples at sea level before departure, and 90 days, 6 months, and 10 months during hypoxia. Samples were analyzed by untargeted liquid chromatography high resolution mass spectrometry to unravel how the non-polar and polar metabolomes are affected. Statistical analyses were performed by clustering the subjects into four groups according to the duration of hypoxia exposure. The non-polar metabolome revealed a modest decrease in the concentration of all the major lipid classes. By contrast, the polar metabolome showed marked alterations in several metabolic pathways, especially those related to amino acids metabolism, with a particular concern of arginine, glutamine, phenylalanine, tryptophan, and tyrosine. Remarkably, all the changes were evident since the first time point and remained unaffected by hypoxia duration (with the exception of a slight return of the non-polar metabolome after 6 months), highlighting a relative inability of the body to compensate them. Finally, we identified a few metabolic pathways that emerged as the main targets of chronic hypoxia.
Collapse
Affiliation(s)
- Michele Dei Cas
- Department of Health Sciences, Università degli Studi di Milano, Milan, Italy
| | - Camillo Morano
- Department of Health Sciences, Università degli Studi di Milano, Milan, Italy
| | - Sara Ottolenghi
- Department of Health Sciences, Università degli Studi di Milano, Milan, Italy
- Department of Medicine and Surgery, Università degli Studi di Milano-Bicocca, Milan, Italy
| | - Roberto Dicasillati
- Department of General Surgery, ASST Santi Paolo e Carlo, San Paolo Hospital, Milan, Italy
| | - Gabriella Roda
- Department of Pharmaceutical Sciences, Università degli Studi di Milano, Milan, Italy
| | - Michele Samaja
- Department of Health Sciences, Università degli Studi di Milano, Milan, Italy
- MAGI Group, Brescia, Italy
- *Correspondence: Michele Samaja,
| | - Rita Paroni
- Department of Health Sciences, Università degli Studi di Milano, Milan, Italy
| |
Collapse
|
29
|
Wearing OH, Nelson D, Ivy CM, Crossley DA, Scott GR. Adrenergic control of the cardiovascular system in deer mice native to high altitude. Curr Res Physiol 2022; 5:83-92. [PMID: 35169714 PMCID: PMC8829085 DOI: 10.1016/j.crphys.2022.01.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 12/23/2021] [Accepted: 01/23/2022] [Indexed: 12/26/2022] Open
Abstract
Studies of animals native to high altitude can provide valuable insight into physiological mechanisms and evolution of performance in challenging environments. We investigated how mechanisms controlling cardiovascular function may have evolved in deer mice (Peromyscus maniculatus) native to high altitude. High-altitude deer mice and low-altitude white-footed mice (P. leucopus) were bred in captivity at sea level, and first-generation lab progeny were raised to adulthood and acclimated to normoxia or hypoxia. We then used pharmacological agents to examine the capacity for adrenergic receptor stimulation to modulate heart rate (fH) and mean arterial pressure (Pmean) in anaesthetized mice, and used cardiac pressure-volume catheters to evaluate the contractility of the left ventricle. We found that highlanders had a consistently greater capacity to increase fH via pharmacological stimulation of β1-adrenergic receptors than lowlanders. Also, whereas hypoxia acclimation reduced the capacity for increasing Pmean in response to α-adrenergic stimulation in lowlanders, highlanders exhibited no plasticity in this capacity. These differences in highlanders may help augment cardiac output during locomotion or cold stress, and may preserve their capacity for α-mediated vasoconstriction to more effectively redistribute blood flow to active tissues. Highlanders did not exhibit any differences in some measures of cardiac contractility (maximum pressure derivative, dP/dtmax, or end-systolic elastance, Ees), but ejection fraction was highest in highlanders after hypoxia acclimation. Overall, our results suggest that evolved changes in sensitivity to adrenergic stimulation of cardiovascular function may help deer mice cope with the cold and hypoxic conditions at high altitude. High-altitude deer mice have evolved increased aerobic capacity in hypoxia. Cardiovascular regulation was examined in normoxia and chronic hypoxia. Highland mice had increased capacity for β1-adrenergic stimulation of heart rate. Hypoxia reduced vascular α-adrenergic sensitivity in lowland but not highland mice. Cardiac ejection fraction was elevated in highland mice in chronic hypoxia.
Collapse
Affiliation(s)
- Oliver H. Wearing
- Department of Biology, McMaster University, Hamilton, ON, Canada
- Corresponding author.
| | - Derek Nelson
- Department of Biological Sciences, University of North Texas, Denton, TX, USA
| | - Catherine M. Ivy
- Department of Biology, McMaster University, Hamilton, ON, Canada
| | - Dane A. Crossley
- Department of Biological Sciences, University of North Texas, Denton, TX, USA
| | - Graham R. Scott
- Department of Biology, McMaster University, Hamilton, ON, Canada
| |
Collapse
|
30
|
Variations in HIF-1α Contributed to High Altitude Hypoxia Adaptation via Affected Oxygen Metabolism in Tibetan Sheep. Animals (Basel) 2021; 12:ani12010058. [PMID: 35011164 PMCID: PMC8749702 DOI: 10.3390/ani12010058] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 12/24/2021] [Accepted: 12/27/2021] [Indexed: 01/19/2023] Open
Abstract
Simple Summary Hypoxia-inducible factors (HIFs) play an important role in the adaptation of animals to high-altitude hypoxia. In high-altitude indigenous species, variation in the hypoxia-inducible factor-1 alpha (HIF-1α) gene has been reported in Tibetans, yaks and Tibetan horses, but has not been investigated in Tibetan sheep, and is not known if it might affect high-altitude hypoxia adaptation in these sheep. In this study, Kompetitive Allele-Specific PCR (KASP) was used for genotyping of ovine HIF-1α and investigated the effect of variation in HIF-1α on the high-altitude hypoxia adaptation of Tibetan sheep. The results suggest that ovine HIF-1α variants may promote the ability of oxygen utilization in Tibetan sheep and it may serve as a genetic marker for improving high-altitude hypoxia adaptability. Abstract The Tibetan sheep is an indigenous species of the Tibetan plateau and has been well adapted to high-altitude hypoxia. In comparison to lowland sheep breeds, the blood gas indicators have changed and the HIFs signaling pathway is activated in Tibetan sheep. These phenotypic and genetic alterations in Tibetan sheep are thought to be an important basis for adaptation to high-altitude hypoxia and variation in genes encoding the subunits that make up HIFs, such as HIF-1α can affect blood gas indicators. In this study, exons 9, 10, 12 of the HIF-1α gene were sequenced to find variations and 3 SNPs were detected, and these 3 SNPs were genotyped by KASP in 341 Hu sheep and 391 Tibetan sheep. In addition, 197 Hu sheep, 160 Tibetan sheep and 12 Gansu alpine merino sheep were used for blood gas indicators analysis. The results showed significant differences between the blood gas indicators of high-altitude breeds (Tibetan sheep and Gansu alpine merino sheep) and low-altitude breeds (Hu sheep), implying that the differences in blood gas indicators are mainly caused by differences in altitude. The haplotype combinations H2H3 and H1H3 were more frequent in the Tibetan sheep population, H2H3 increases O2 carrying capacity by increasing hematocrit and hemoglobin concentrations; H1H3 makes O2 dissociate more readily from oxyhemoglobin by decreasing partial pressure of oxygen and oxygen saturation. These results suggest that variants at the HIF-1α promote the ability of oxygen utilization in Tibetan sheep, which may underpin the survival and reproduction of Tibetan sheep on the Tibetan plateau.
Collapse
|
31
|
Gonzalez-Candia A, Herrera EA. High Altitude Pregnancies and Vascular Dysfunction: Observations From Latin American Studies. Front Physiol 2021; 12:786038. [PMID: 34950057 PMCID: PMC8688922 DOI: 10.3389/fphys.2021.786038] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 11/02/2021] [Indexed: 12/14/2022] Open
Abstract
An estimated human population of 170 million inhabit at high-altitude (HA, above 2,500 m). The potential pathological effects of HA hypobaric hypoxia during gestation have been the focus of several researchers around the world. The studies based on the Himalayan and Central/South American mountains are particularly interesting as these areas account for nearly 70% of the HA world population. At present, studies in human and animal models revealed important alterations in fetal development and growth at HA. Moreover, vascular responses to chronic hypobaria in the pregnant mother and her fetus may induce marked cardiovascular impairments during pregnancy or in the neonatal period. In addition, recent studies have shown potential long-lasting postnatal effects that may increase cardiovascular risk in individuals gestated under chronic hypobaria. Hence, the maternal and fetal adaptive responses to hypoxia, influenced by HA ancestry, are vital for a better developmental and cardiovascular outcome of the offspring. This mini-review exposes and discusses the main determinants of vascular dysfunction due to developmental hypoxia at HA, such as the Andean Mountains, at the maternal and fetal/neonatal levels. Although significant advances have been made from Latin American studies, this area still needs further investigations to reveal the mechanisms involved in vascular dysfunction, to estimate complications of pregnancy and postnatal life adequately, and most importantly, to determine potential treatments to prevent or treat the pathological effects of being developed under chronic hypobaric hypoxia.
Collapse
Affiliation(s)
- Alejandro Gonzalez-Candia
- Laboratorio de Función y Reactividad Vascular, Programa de Fisiopatología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.,Instituto de Ciencias de la Salud, Universidad de O'Higgins, Rancagua, Chile
| | - Emilio A Herrera
- Laboratorio de Función y Reactividad Vascular, Programa de Fisiopatología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.,International Center for Andean Studies (INCAS), Universidad de Chile, Santiago, Chile
| |
Collapse
|
32
|
Li F, Qiao Z, Duan Q, Nevo E. Adaptation of mammals to hypoxia. Animal Model Exp Med 2021; 4:311-318. [PMID: 34977482 PMCID: PMC8690989 DOI: 10.1002/ame2.12189] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Revised: 10/27/2021] [Accepted: 10/31/2021] [Indexed: 12/19/2022] Open
Abstract
Oxygen plays a pivotal role in the metabolism and activities of mammals. However, oxygen is restricted in some environments-subterranean burrow systems or habitats at high altitude or deep in the ocean-and this could exert hypoxic stresses such as oxidative damage on organisms living in these environments. In order to cope with these stresses, organisms have evolved specific strategies to adapt to hypoxia, including changes in physiology, gene expression regulation, and genetic mutations. Here, we review how mammals have adapted to the three high-altitude plateaus of the world, the limited oxygen dissolved in deep water habitats, and underground tunnels, with the aim of better understanding the adaptation of mammals to hypoxia.
Collapse
Affiliation(s)
- Fang Li
- College of Life Sciences and TechnologyMudanjiang Normal UniversityMudanjiangChina
| | - Zhenglei Qiao
- College of Life Sciences and TechnologyMudanjiang Normal UniversityMudanjiangChina
| | - Qijiao Duan
- College of Natural Resources and EnvironmentSouth China Agriculture UniversityGuangzhouChina
| | - Eviatar Nevo
- Institute of EvolutionUniversity of HaifaHaifaIsrael
| |
Collapse
|
33
|
Premont RT, Singel DJ, Stamler JS. The enzymatic function of the honorary enzyme: S-nitrosylation of hemoglobin in physiology and medicine. Mol Aspects Med 2021; 84:101056. [PMID: 34852941 DOI: 10.1016/j.mam.2021.101056] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 11/22/2021] [Accepted: 11/24/2021] [Indexed: 11/16/2022]
Abstract
The allosteric transition within tetrameric hemoglobin (Hb) that allows both full binding to four oxygen molecules in the lung and full release of four oxygens in hypoxic tissues would earn Hb the moniker of 'honorary enzyme'. However, the allosteric model for oxygen binding in hemoglobin overlooked the essential role of blood flow in tissue oxygenation that is essential for life (aka autoregulation of blood flow). That is, blood flow, not oxygen content of blood, is the principal determinant of oxygen delivery under most conditions. With the discovery that hemoglobin carries a third biologic gas, nitric oxide (NO) in the form of S-nitrosothiol (SNO) at β-globin Cys93 (βCys93), and that formation and export of SNO to dilate blood vessels are linked to hemoglobin allostery through enzymatic activity, this title is honorary no more. This chapter reviews evidence that hemoglobin formation and release of SNO is a critical mediator of hypoxic autoregulation of blood flow in tissues leading to oxygen delivery, considers the physiological implications of a 3-gas respiratory cycle (O2/NO/CO2) and the pathophysiological consequences of its dysfunction. Opportunities for therapeutic intervention to optimize oxygen delivery at the level of tissue blood flow are highlighted.
Collapse
Affiliation(s)
- Richard T Premont
- Institute for Transformative Molecular Medicine, Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA; Harrington Discovery Institute, University Hospitals Cleveland Medical Center, Cleveland, OH, 44106, USA
| | - David J Singel
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT, 59717, USA
| | - Jonathan S Stamler
- Institute for Transformative Molecular Medicine, Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA; Harrington Discovery Institute, University Hospitals Cleveland Medical Center, Cleveland, OH, 44106, USA.
| |
Collapse
|
34
|
Moreira LDSG, Fanton S, Cardozo L, Borges NA, Combet E, Shiels PG, Stenvinkel P, Mafra D. Pink pressure: beetroot (Beta vulgaris rubra) as a possible novel medical therapy for chronic kidney disease. Nutr Rev 2021; 80:1041-1061. [PMID: 34613396 DOI: 10.1093/nutrit/nuab074] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Chronic kidney disease (CKD) manifests with systemic inflammation, oxidative stress, and gut dysbiosis, resulting in metabolic disorders and elevated rates of cardiovascular disease-associated death. These all correlate with a high economic cost to healthcare systems. Growing evidence indicates that diet is an indispensable ally in the prevention and management of CKD and its complications. In this context, the root vegetable beetroot (Beta vulgaris rubra) deserves special attention because it is a source of several bioactive compounds, such as nitrate, betaine, and betalain, and has shown beneficial effects in CKD, including reduction of blood pressure, anti-inflammatory effects, and antioxidant actions by scavenging radical oxidative species, as observed in preclinical studies. Beetroot consumption as a possible therapeutic strategy to improve the clinical treatment of patients with CKD and future directions for clinical studies are addressed in this narrative review.
Collapse
Affiliation(s)
- Laís de Souza Gouveia Moreira
- L.d.S.G. Moreira and D. Mafra are with the Graduate Program in Medical Sciences, Fluminense Federal University, Niterói, Rio de Janiero, Brazil. S. Fanton, L. Cardozo, and D. Mafra are with the Graduate Program in Cardiovascular Sciences, Federal Fluminense University, Niterói-Rio de Janeiro, RJ, Brazil. N.A. Borges is with the Institute of Nutrition, State University of Rio de Janeiro, Rio de Janeiro, Brazil. E. Combet is with the School of Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom. P.G. Shiels is with the Wolfson Wohl Translational Research Centre, Institute of Cancer Sciences, University of Glasgow, Glasgow, United Kingdom. P. Stenvinkel is with the Department of Renal Medicine, Karolinska University Hospital, Stockholm, Sweden
| | - Susane Fanton
- L.d.S.G. Moreira and D. Mafra are with the Graduate Program in Medical Sciences, Fluminense Federal University, Niterói, Rio de Janiero, Brazil. S. Fanton, L. Cardozo, and D. Mafra are with the Graduate Program in Cardiovascular Sciences, Federal Fluminense University, Niterói-Rio de Janeiro, RJ, Brazil. N.A. Borges is with the Institute of Nutrition, State University of Rio de Janeiro, Rio de Janeiro, Brazil. E. Combet is with the School of Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom. P.G. Shiels is with the Wolfson Wohl Translational Research Centre, Institute of Cancer Sciences, University of Glasgow, Glasgow, United Kingdom. P. Stenvinkel is with the Department of Renal Medicine, Karolinska University Hospital, Stockholm, Sweden
| | - Ludmila Cardozo
- L.d.S.G. Moreira and D. Mafra are with the Graduate Program in Medical Sciences, Fluminense Federal University, Niterói, Rio de Janiero, Brazil. S. Fanton, L. Cardozo, and D. Mafra are with the Graduate Program in Cardiovascular Sciences, Federal Fluminense University, Niterói-Rio de Janeiro, RJ, Brazil. N.A. Borges is with the Institute of Nutrition, State University of Rio de Janeiro, Rio de Janeiro, Brazil. E. Combet is with the School of Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom. P.G. Shiels is with the Wolfson Wohl Translational Research Centre, Institute of Cancer Sciences, University of Glasgow, Glasgow, United Kingdom. P. Stenvinkel is with the Department of Renal Medicine, Karolinska University Hospital, Stockholm, Sweden
| | - Natalia A Borges
- L.d.S.G. Moreira and D. Mafra are with the Graduate Program in Medical Sciences, Fluminense Federal University, Niterói, Rio de Janiero, Brazil. S. Fanton, L. Cardozo, and D. Mafra are with the Graduate Program in Cardiovascular Sciences, Federal Fluminense University, Niterói-Rio de Janeiro, RJ, Brazil. N.A. Borges is with the Institute of Nutrition, State University of Rio de Janeiro, Rio de Janeiro, Brazil. E. Combet is with the School of Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom. P.G. Shiels is with the Wolfson Wohl Translational Research Centre, Institute of Cancer Sciences, University of Glasgow, Glasgow, United Kingdom. P. Stenvinkel is with the Department of Renal Medicine, Karolinska University Hospital, Stockholm, Sweden
| | - Emilie Combet
- L.d.S.G. Moreira and D. Mafra are with the Graduate Program in Medical Sciences, Fluminense Federal University, Niterói, Rio de Janiero, Brazil. S. Fanton, L. Cardozo, and D. Mafra are with the Graduate Program in Cardiovascular Sciences, Federal Fluminense University, Niterói-Rio de Janeiro, RJ, Brazil. N.A. Borges is with the Institute of Nutrition, State University of Rio de Janeiro, Rio de Janeiro, Brazil. E. Combet is with the School of Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom. P.G. Shiels is with the Wolfson Wohl Translational Research Centre, Institute of Cancer Sciences, University of Glasgow, Glasgow, United Kingdom. P. Stenvinkel is with the Department of Renal Medicine, Karolinska University Hospital, Stockholm, Sweden
| | - Paul G Shiels
- L.d.S.G. Moreira and D. Mafra are with the Graduate Program in Medical Sciences, Fluminense Federal University, Niterói, Rio de Janiero, Brazil. S. Fanton, L. Cardozo, and D. Mafra are with the Graduate Program in Cardiovascular Sciences, Federal Fluminense University, Niterói-Rio de Janeiro, RJ, Brazil. N.A. Borges is with the Institute of Nutrition, State University of Rio de Janeiro, Rio de Janeiro, Brazil. E. Combet is with the School of Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom. P.G. Shiels is with the Wolfson Wohl Translational Research Centre, Institute of Cancer Sciences, University of Glasgow, Glasgow, United Kingdom. P. Stenvinkel is with the Department of Renal Medicine, Karolinska University Hospital, Stockholm, Sweden
| | - Peter Stenvinkel
- L.d.S.G. Moreira and D. Mafra are with the Graduate Program in Medical Sciences, Fluminense Federal University, Niterói, Rio de Janiero, Brazil. S. Fanton, L. Cardozo, and D. Mafra are with the Graduate Program in Cardiovascular Sciences, Federal Fluminense University, Niterói-Rio de Janeiro, RJ, Brazil. N.A. Borges is with the Institute of Nutrition, State University of Rio de Janeiro, Rio de Janeiro, Brazil. E. Combet is with the School of Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom. P.G. Shiels is with the Wolfson Wohl Translational Research Centre, Institute of Cancer Sciences, University of Glasgow, Glasgow, United Kingdom. P. Stenvinkel is with the Department of Renal Medicine, Karolinska University Hospital, Stockholm, Sweden
| | - Denise Mafra
- L.d.S.G. Moreira and D. Mafra are with the Graduate Program in Medical Sciences, Fluminense Federal University, Niterói, Rio de Janiero, Brazil. S. Fanton, L. Cardozo, and D. Mafra are with the Graduate Program in Cardiovascular Sciences, Federal Fluminense University, Niterói-Rio de Janeiro, RJ, Brazil. N.A. Borges is with the Institute of Nutrition, State University of Rio de Janeiro, Rio de Janeiro, Brazil. E. Combet is with the School of Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom. P.G. Shiels is with the Wolfson Wohl Translational Research Centre, Institute of Cancer Sciences, University of Glasgow, Glasgow, United Kingdom. P. Stenvinkel is with the Department of Renal Medicine, Karolinska University Hospital, Stockholm, Sweden
| |
Collapse
|
35
|
Sharma K, Chanana N, Mohammad G, Thinlas T, Gupta M, Syed MA, Das RS, Pasha Q, Mishra A. Hypertensive Patients Exhibit Enhanced Thrombospondin-1 Levels at High-Altitude. Life (Basel) 2021; 11:life11090893. [PMID: 34575042 PMCID: PMC8469964 DOI: 10.3390/life11090893] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 08/22/2021] [Accepted: 08/23/2021] [Indexed: 12/18/2022] Open
Abstract
Thrombospondin-1 (THBS1) levels elevate under hypoxia and have relevance in several cardiovascular disorders. The association of THBS1 with endothelial dysfunction implies its important role in hypertension. To establish the hypothesis, we screened patients with hypertension and their respective controls from the two different environmental regions. Cohort 1 was composed of Ladakhis, residing at 3500 m above sea level (ASL), whereas Cohort 2 was composed of north-Indians residing at ~200 m ASL. Clinical parameters and circulating THBS1 levels were correlated in the case–control groups of the two populations. THBS1 levels were significantly elevated in hypertension patients of both cohorts; however, the levels were distinctly enhanced in the hypertensive patients of HA as compared to normoxia (p < 0.002). The observation was supported by the receiver operating curve analysis with an area under curve of 0.7007 (0.627–0.774) demonstrating the discriminatory effect of hypobaric hypoxia on the levels as compared to normoxia (p < 0.011). Significant correlation of THBS1 and mean arterial pressure was observed with upraised positive correlations in the hypertensive highlanders as compared to the hypertensive patients from sea-level. The prevalence of differential distribution of THBS1 and CD47 genes variants, their interactions, and association with the THBS1 levels were also determined. Genotype-interactions between THBS1 rs2228263 and CD47 rs9879947 were relevant and the regression analysis highlighted the association of risk genotype-interactions with increased THBS1 levels in hypertension. Genetic studies of additional thrombospondin pathway-related genes suggest the complex role of THBS1 in the presence of its family members and the related receptor molecules at HA.
Collapse
Affiliation(s)
- Kavita Sharma
- Cardiovascular Respiratory Disease Unit, CSIR-Institute of Genomics and Integrative Biology, Delhi 110007, India; (K.S.); (N.C.); (Q.P.)
- Department of Biotechnology, Jamia Millia Islamia, New Delhi 110025, India;
| | - Neha Chanana
- Cardiovascular Respiratory Disease Unit, CSIR-Institute of Genomics and Integrative Biology, Delhi 110007, India; (K.S.); (N.C.); (Q.P.)
| | - Ghulam Mohammad
- Department of Medicine, SNM Hospital, Leh 194101, India; (G.M.); (T.T.)
| | - Tashi Thinlas
- Department of Medicine, SNM Hospital, Leh 194101, India; (G.M.); (T.T.)
| | - Mohit Gupta
- Department of Cardiology, GB Pant Institute of Post Graduate Medical Education and Research, New Delhi 110002, India;
| | - Mansoor Ali Syed
- Department of Biotechnology, Jamia Millia Islamia, New Delhi 110025, India;
| | - Rajat Subhra Das
- Department of Anatomy, All India Institute of Medical Sciences, Raebareli 229405, India;
| | - Qadar Pasha
- Cardiovascular Respiratory Disease Unit, CSIR-Institute of Genomics and Integrative Biology, Delhi 110007, India; (K.S.); (N.C.); (Q.P.)
- Indian Council of Medical Research, New Delhi 110029, India
| | - Aastha Mishra
- Cardiovascular Respiratory Disease Unit, CSIR-Institute of Genomics and Integrative Biology, Delhi 110007, India; (K.S.); (N.C.); (Q.P.)
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
- Correspondence:
| |
Collapse
|
36
|
Hansen AB, Moralez G, Amin SB, Simspon LL, Hofstaetter F, Anholm JD, Gasho C, Stembridge M, Dawkins TG, Tymko MM, Ainslie PN, Villafuerte F, Romero SA, Hearon CM, Lawley JS. Global REACH 2018: the adaptive phenotype to life with chronic mountain sickness and polycythaemia. J Physiol 2021; 599:4021-4044. [PMID: 34245004 DOI: 10.1113/jp281730] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 06/18/2021] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS Humans suffering from polycythaemia undergo multiple circulatory adaptations including changes in blood rheology and structural and functional vascular adaptations to maintain normal blood pressure and vascular shear stresses, despite high blood viscosity. During exercise, several circulatory adaptations are observed, especially involving adrenergic and non-adrenergic mechanisms within non-active and active skeletal muscle to maintain exercise capacity, which is not observed in animal models. Despite profound circulatory stress, i.e. polycythaemia, several adaptations can occur to maintain exercise capacity, therefore making early identification of the disease difficult without overt symptomology. Pharmacological treatment of the background heightened sympathetic activity may impair the adaptive sympathetic response needed to match local oxygen delivery to active skeletal muscle oxygen demand and therefore inadvertently impair exercise capacity. ABSTRACT Excessive haematocrit and blood viscosity can increase blood pressure, cardiac work and reduce aerobic capacity. However, past clinical investigations have demonstrated that certain human high-altitude populations suffering from excessive erythrocytosis, Andeans with chronic mountain sickness, appear to have phenotypically adapted to life with polycythaemia, as their exercise capacity is comparable to healthy Andeans and even with sea-level inhabitants residing at high altitude. By studying this unique population, which has adapted through natural selection, this study aimed to describe how humans can adapt to life with polycythaemia. Experimental studies included Andeans with (n = 19) and without (n = 17) chronic mountain sickness, documenting exercise capacity and characterizing the transport of oxygen through blood rheology, including haemoglobin mass, blood and plasma volume and blood viscosity, cardiac output, blood pressure and changes in total and local vascular resistances through pharmacological dissection of α-adrenergic signalling pathways within non-active and active skeletal muscle. At rest, Andeans with chronic mountain sickness had a substantial plasma volume contraction, which alongside a higher red blood cell volume, caused an increase in blood viscosity yet similar total blood volume. Moreover, both morphological and functional alterations in the periphery normalized vascular shear stress and blood pressure despite high sympathetic nerve activity. During exercise, blood pressure, cardiac work and global oxygen delivery increased similar to healthy Andeans but were sustained by modifications in both non-active and active skeletal muscle vascular function. These findings highlight widespread physiological adaptations that can occur in response to polycythaemia, which allow the maintenance of exercise capacity.
Collapse
Affiliation(s)
- Alexander B Hansen
- Department of Sport Science, Division of Performance Physiology and Prevention, University of Innsbruck, Innsbruck, Austria
| | - Gilbert Moralez
- Department of Applied Clinical Research, University of Southwestern Medical Center, Dallas, Texas, USA
| | - Sachin B Amin
- Department of Sport Science, Division of Performance Physiology and Prevention, University of Innsbruck, Innsbruck, Austria
| | - Lydia L Simspon
- Department of Sport Science, Division of Performance Physiology and Prevention, University of Innsbruck, Innsbruck, Austria
| | - Florian Hofstaetter
- Department of Sport Science, Division of Performance Physiology and Prevention, University of Innsbruck, Innsbruck, Austria
| | - James D Anholm
- Department of Medicine, Division of Pulmonary and Critical Care, Loma Linda University, Loma Linda, California, USA
| | - Christopher Gasho
- Department of Medicine, Division of Pulmonary and Critical Care, Loma Linda University, Loma Linda, California, USA
| | - Mike Stembridge
- Cardiff School of Sport and Health Sciences, Cardiff Metropolitan University, Cardiff, UK
| | - Tony G Dawkins
- Cardiff School of Sport and Health Sciences, Cardiff Metropolitan University, Cardiff, UK
| | - Michael M Tymko
- Physical Activity and Diabetes Laboratory, Faculty of Kinesiology, Sport and Recreation, University of Alberta, Edmonton, Alberta, Canada.,Centre of Heart, Lung, and Vascular Health, School of Health and Exercise Sciences, University of British Columbia - Okanagan, Kelowna, British Columbia, Canada
| | - Philip N Ainslie
- Centre of Heart, Lung, and Vascular Health, School of Health and Exercise Sciences, University of British Columbia - Okanagan, Kelowna, British Columbia, Canada
| | - Francisco Villafuerte
- Laboratorio de Fisiología Comparada/Fisiología del Transporte de Oxígeno, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Steven A Romero
- University of North Texas Health Science Center, Fort Worth, Texas, USA
| | - Christopher M Hearon
- Department of Applied Clinical Research, University of Southwestern Medical Center, Dallas, Texas, USA.,Institute of Exercise and Environmental Medicine, Texas Health Presbyterian Dallas, Dallas, Texas, USA
| | - Justin S Lawley
- Department of Sport Science, Division of Performance Physiology and Prevention, University of Innsbruck, Innsbruck, Austria
| |
Collapse
|
37
|
Liu H, Hu YJ, Zheng SQ, Chen T, Zeng ZH, Wu DD, Zhao S, Zeng B, Liu ZG, Shao YF. Effect of perfusate oxygenation on inflammatory response in congenital heart disease children from low versus high altitude. J Thorac Cardiovasc Surg 2021; 161:2180-2190. [DOI: 10.1016/j.jtcvs.2020.05.108] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Revised: 05/13/2020] [Accepted: 05/31/2020] [Indexed: 10/24/2022]
|
38
|
Marshall AR, Rimmer JE, Shah N, Bye K, Kipps C, Woods DR, O'Hara J, Boos CJ, Barlow M. Marching to the Beet: The effect of dietary nitrate supplementation on high altitude exercise performance and adaptation during a military trekking expedition. Nitric Oxide 2021; 113-114:70-77. [PMID: 34051342 DOI: 10.1016/j.niox.2021.05.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 03/19/2021] [Accepted: 05/23/2021] [Indexed: 10/21/2022]
Abstract
PURPOSE The aim was to investigate the effect of dietary nitrate supplementation (in the form of beetroot juice, BRJ) for 20 days on salivary nitrite (a potential precursor of bioactive nitric oxide), exercise performance and high altitude (HA) acclimatisation in field conditions (hypobaric hypoxia). METHODS This was a single-blinded randomised control study of 22 healthy adult participants (12 men, 10 women, mean age 28 ± 12 years) across a HA military expedition. Participants were randomised pre-ascent to receive two 70 ml dose per day of either BRJ (~12.5 mmol nitrate per day; n = 11) or non-nitrate calorie matched control (n = 11). Participants ingested supplement doses daily, beginning 3 days prior to departure and continued until the highest sleeping altitude (4800 m) reached on day 17 of the expedition. Data were collected at baseline (44 m altitude), at 2350 m (day 9), 3400 m (day 12) and 4800 m (day 17). RESULTS BRJ enhanced the salivary levels of nitrite (p = 0.007). There was a significant decrease in peripheral oxygen saturation and there were increases in heart rate, diastolic blood pressure, and rating of perceived exertion with increasing altitude (p=<0.001). Harvard Step Test fitness scores significantly declined at 4800 m in the control group (p = 0.003) compared with baseline. In contrast, there was no decline in fitness scores at 4800 m compared with baseline (p = 0.26) in the BRJ group. Heart rate recovery speed following exercise at 4800 m was significantly prolonged in the control group (p=<0.01) but was unchanged in the BRJ group (p = 0.61). BRJ did not affect the burden of HA illness (p = 1.00). CONCLUSIONS BRJ increases salivary nitrite levels and ameliorates the decline in fitness at altitude but does not affect the occurrence of HA illness.
Collapse
Affiliation(s)
- Anna R Marshall
- Department of Surgical and Interventional Sciences, Institute of Sport, Exercise & Health, UCL, London, WC1E 6B, UK.
| | | | - Nishma Shah
- Department of Surgical and Interventional Sciences, Institute of Sport, Exercise & Health, UCL, London, WC1E 6B, UK
| | - Kyo Bye
- Defence Medical Services, Lichfield, WS14 9PY, UK
| | - Courtney Kipps
- Department of Surgical and Interventional Sciences, Institute of Sport, Exercise & Health, UCL, London, WC1E 6B, UK
| | - David R Woods
- Defence Medical Services, Lichfield, WS14 9PY, UK; Carneige School of Sport, Leeds Beckett University, Leeds, LS16 5LF, UK; Northumbria and Newcastle NHS Trusts, Wansbeck General and Royal Victoria Infirmary, Newcastle, NE66 2NS, UK
| | - John O'Hara
- Carneige School of Sport, Leeds Beckett University, Leeds, LS16 5LF, UK
| | - Christopher J Boos
- Carneige School of Sport, Leeds Beckett University, Leeds, LS16 5LF, UK; Department of Cardiology, Poole Hospital NHS Foundation Trust, Poole, BH15 2JB, UK; Department of Postgraduate Medical Education, Bournemouth University, Bournemouth, BH1 3LT, UK
| | - Matthew Barlow
- Carneige School of Sport, Leeds Beckett University, Leeds, LS16 5LF, UK
| |
Collapse
|
39
|
Pham K, Parikh K, Heinrich EC. Hypoxia and Inflammation: Insights From High-Altitude Physiology. Front Physiol 2021; 12:676782. [PMID: 34122145 PMCID: PMC8188852 DOI: 10.3389/fphys.2021.676782] [Citation(s) in RCA: 77] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Accepted: 04/26/2021] [Indexed: 12/19/2022] Open
Abstract
The key regulators of the transcriptional response to hypoxia and inflammation (hypoxia inducible factor, HIF, and nuclear factor-kappa B, NF-κB, respectively) are evolutionarily conserved and share significant crosstalk. Tissues often experience hypoxia and inflammation concurrently at the site of infection or injury due to fluid retention and immune cell recruitment that ultimately reduces the rate of oxygen delivery to tissues. Inflammation can induce activity of HIF-pathway genes, and hypoxia may modulate inflammatory signaling. While it is clear that these molecular pathways function in concert, the physiological consequences of hypoxia-induced inflammation and how hypoxia modulates inflammatory signaling and immune function are not well established. In this review, we summarize known mechanisms of HIF and NF-κB crosstalk and highlight the physiological consequences that can arise from maladaptive hypoxia-induced inflammation. Finally, we discuss what can be learned about adaptive regulation of inflammation under chronic hypoxia by examining adaptive and maladaptive inflammatory phenotypes observed in human populations at high altitude. We aim to provide insight into the time domains of hypoxia-induced inflammation and highlight the importance of hypoxia-induced inflammatory sensitization in immune function, pathologies, and environmental adaptation.
Collapse
Affiliation(s)
| | | | - Erica C. Heinrich
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, Riverside, CA, United States
| |
Collapse
|
40
|
Zheng H, Wei XC, Yu T, Lei Q. Anesthesia of a high-altitude area inhabitant who underwent aortic dissection emergency surgery in a low-altitude area. J Int Med Res 2021; 48:300060520979871. [PMID: 33349120 PMCID: PMC7758670 DOI: 10.1177/0300060520979871] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Heart surgery in patients from high-altitude areas is more challenging than usual. Few studies have been published on this issue, and none of them have discussed the effect of an altitude change (from high to low altitude) on a patient’s physiology or its effects on a patient’s perioperative management. Here, we present the case of a 46-year-old man who was a long-time resident of Tibetan area in Sichuan (altitude >3000 m) who underwent Stanford type A aortic dissection emergency surgery on the plain. Anesthetic management occurred through monitoring of the bispectral index (BIS) and transesophageal echocardiography (TEE), and we used a relatively loose fluid hydration strategy. The surgery was performed using cardiopulmonary bypass (CPB), deep hypothermia (DH), and selective antegrade cerebral perfusion. The most prominent anesthesia challenges for these patients are physiological changes due to habitation in an high-altitude environment (chronic hypoxemia), which can cause hyperhemoglobinemia, polycythemia, hypercoagulable blood, and even pulmonary hypertension, cor pulmonale, or congestive heart failure. Optimized perioperative management and close cooperation among the entire cardiac medical team were the key factors in the successful management of this rare case.
Collapse
Affiliation(s)
- Huan Zheng
- Department of Anesthesiology, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China.,Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, Chengdu, China
| | - Xin-Chuan Wei
- Department of Anesthesiology, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China.,Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, Chengdu, China
| | - Tao Yu
- Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, Chengdu, China.,Department of Cardiovascular Surgery, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
| | - Qian Lei
- Department of Anesthesiology, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China.,Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, Chengdu, China
| |
Collapse
|
41
|
Serra-Payá N, Garnacho-Castaño MV, Sánchez-Nuño S, Albesa-Albiol L, Girabent-Farrés M, Moizé Arcone L, Fernández AP, García-Fresneda A, Castizo-Olier J, Viñals X, Molina-Raya L, Gomis Bataller M. The Relationship between Resistance Exercise Performance and Ventilatory Efficiency after Beetroot Juice Intake in Well-Trained Athletes. Nutrients 2021; 13:nu13041094. [PMID: 33801665 PMCID: PMC8065812 DOI: 10.3390/nu13041094] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Revised: 03/17/2021] [Accepted: 03/25/2021] [Indexed: 11/16/2022] Open
Abstract
The assessment of ventilatory efficiency is critical to understanding the matching of ventilation (VE) and perfusion in the lungs during exercise. This study aimed to establish a causal physiological relationship between ventilatory efficiency and resistance exercise performance after beetroot juice (BJ) intake. Eleven well-trained males performed a resistance exercise test after drinking 140 mL of BJ (~12.8 mmol NO3-) or a placebo (PL). Ventilatory efficiency was assessed by the VE•VCO2-1 slope, the oxygen uptake efficiency slope and the partial pressure of end-tidal carbon dioxide (PetCO2). The two experimental conditions were controlled using a randomized, double-blind crossover design. The resistance exercise test involved repeating the same routine twice, which consisted of wall ball shots plus a full squat (FS) with a 3 min rest or without a rest between the two exercises. A higher weight lifted was detected in the FS exercise after BJ intake compared with the PL during the first routine (p = 0.004). BJ improved the VE•VCO2-1 slope and the PetCO2 during the FS exercise in the first routine and at rest (p < 0.05). BJ intake improved the VE•VCO2-1 slope and the PetCO2 coinciding with the resistance exercise performance. The ergogenic effect of BJ could be induced under aerobic conditions at rest.
Collapse
Affiliation(s)
- Noemí Serra-Payá
- School of Health Sciences, TecnoCampus Pompeu Fabra University, Ernest Lluch, 32 (Porta Laietana), 08302 Mataró-Barcelona, Spain; (N.S.-P.); (S.S.-N.); (L.A.-A.); (M.G.-F.); (L.M.A.); (A.P.F.); (A.G.-F.); (J.C.-O.); (X.V.); (M.G.B.)
| | - Manuel Vicente Garnacho-Castaño
- School of Health Sciences, TecnoCampus Pompeu Fabra University, Ernest Lluch, 32 (Porta Laietana), 08302 Mataró-Barcelona, Spain; (N.S.-P.); (S.S.-N.); (L.A.-A.); (M.G.-F.); (L.M.A.); (A.P.F.); (A.G.-F.); (J.C.-O.); (X.V.); (M.G.B.)
- Correspondence: ; Tel.: +34-606275392
| | - Sergio Sánchez-Nuño
- School of Health Sciences, TecnoCampus Pompeu Fabra University, Ernest Lluch, 32 (Porta Laietana), 08302 Mataró-Barcelona, Spain; (N.S.-P.); (S.S.-N.); (L.A.-A.); (M.G.-F.); (L.M.A.); (A.P.F.); (A.G.-F.); (J.C.-O.); (X.V.); (M.G.B.)
| | - Lluís Albesa-Albiol
- School of Health Sciences, TecnoCampus Pompeu Fabra University, Ernest Lluch, 32 (Porta Laietana), 08302 Mataró-Barcelona, Spain; (N.S.-P.); (S.S.-N.); (L.A.-A.); (M.G.-F.); (L.M.A.); (A.P.F.); (A.G.-F.); (J.C.-O.); (X.V.); (M.G.B.)
| | - Montserrat Girabent-Farrés
- School of Health Sciences, TecnoCampus Pompeu Fabra University, Ernest Lluch, 32 (Porta Laietana), 08302 Mataró-Barcelona, Spain; (N.S.-P.); (S.S.-N.); (L.A.-A.); (M.G.-F.); (L.M.A.); (A.P.F.); (A.G.-F.); (J.C.-O.); (X.V.); (M.G.B.)
| | - Luciana Moizé Arcone
- School of Health Sciences, TecnoCampus Pompeu Fabra University, Ernest Lluch, 32 (Porta Laietana), 08302 Mataró-Barcelona, Spain; (N.S.-P.); (S.S.-N.); (L.A.-A.); (M.G.-F.); (L.M.A.); (A.P.F.); (A.G.-F.); (J.C.-O.); (X.V.); (M.G.B.)
| | - Alba Pardo Fernández
- School of Health Sciences, TecnoCampus Pompeu Fabra University, Ernest Lluch, 32 (Porta Laietana), 08302 Mataró-Barcelona, Spain; (N.S.-P.); (S.S.-N.); (L.A.-A.); (M.G.-F.); (L.M.A.); (A.P.F.); (A.G.-F.); (J.C.-O.); (X.V.); (M.G.B.)
| | - Adrián García-Fresneda
- School of Health Sciences, TecnoCampus Pompeu Fabra University, Ernest Lluch, 32 (Porta Laietana), 08302 Mataró-Barcelona, Spain; (N.S.-P.); (S.S.-N.); (L.A.-A.); (M.G.-F.); (L.M.A.); (A.P.F.); (A.G.-F.); (J.C.-O.); (X.V.); (M.G.B.)
| | - Jorge Castizo-Olier
- School of Health Sciences, TecnoCampus Pompeu Fabra University, Ernest Lluch, 32 (Porta Laietana), 08302 Mataró-Barcelona, Spain; (N.S.-P.); (S.S.-N.); (L.A.-A.); (M.G.-F.); (L.M.A.); (A.P.F.); (A.G.-F.); (J.C.-O.); (X.V.); (M.G.B.)
| | - Xavier Viñals
- School of Health Sciences, TecnoCampus Pompeu Fabra University, Ernest Lluch, 32 (Porta Laietana), 08302 Mataró-Barcelona, Spain; (N.S.-P.); (S.S.-N.); (L.A.-A.); (M.G.-F.); (L.M.A.); (A.P.F.); (A.G.-F.); (J.C.-O.); (X.V.); (M.G.B.)
| | - Lorena Molina-Raya
- Campus Docent Sant Joan de Déu, Fundación Privada, 08304 Barcelona, Spain;
| | - Manuel Gomis Bataller
- School of Health Sciences, TecnoCampus Pompeu Fabra University, Ernest Lluch, 32 (Porta Laietana), 08302 Mataró-Barcelona, Spain; (N.S.-P.); (S.S.-N.); (L.A.-A.); (M.G.-F.); (L.M.A.); (A.P.F.); (A.G.-F.); (J.C.-O.); (X.V.); (M.G.B.)
| |
Collapse
|
42
|
Fan JL, Wu TY, Lovering AT, Nan L, Bang WL, Kayser B. Differential Brain and Muscle Tissue Oxygenation Responses to Exercise in Tibetans Compared to Han Chinese. Front Physiol 2021; 12:617954. [PMID: 33716766 PMCID: PMC7943468 DOI: 10.3389/fphys.2021.617954] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 01/18/2021] [Indexed: 11/13/2022] Open
Abstract
The Tibetans’ better aerobic exercise capacity at altitude remains ill-understood. We tested the hypothesis that Tibetans display better muscle and brain tissue oxygenation during exercise in hypoxia. Using near-infrared spectrometry (NIRS) to provide indices of tissue oxygenation, we measured oxy- and deoxy-hemoglobin ([O2Hb] and [HHb], respectively) responses of the vastus lateralis muscle and the right prefrontal cortex in ten Han Chinese and ten Tibetans during incremental cycling to exhaustion in a pressure-regulated chamber at simulated sea-level (air at 1 atm: normobaric normoxia) and 5,000 m (air at 0.5 atm: hypobaric hypoxia). Hypoxia reduced aerobic capacity by ∼22% in both groups (d = 0.8, p < 0.001 vs. normoxia), while Tibetans consistently outperformed their Han Chinese counterpart by ∼32% in normoxia and hypoxia (d = 1.0, p = 0.008). We found cerebral [O2Hb] was higher in Tibetans at normoxic maximal effort compared Han (p = 0.001), while muscle [O2Hb] was not different (p = 0.240). Hypoxic exercise lowered muscle [O2Hb] in Tibetans by a greater extent than in Han (interaction effect: p < 0.001 vs. normoxic exercise). Muscle [O2Hb] was lower in Tibetans when compared to Han during hypoxic exercise (d = 0.9, p = 0.003), but not during normoxic exercise (d = 0.4, p = 0.240). Muscle [HHb] was not different between the two groups during normoxic and hypoxic exercise (p = 0.778). Compared to Han, our findings revealed a higher brain tissue oxygenation in Tibetans during maximal exercise in normoxia, but lower muscle tissue oxygenation during exercise in hypoxia. This would suggest that the Tibetans privileged oxygenation of the brain at the expense of that of the muscle.
Collapse
Affiliation(s)
- Jui-Lin Fan
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Tian Yi Wu
- Research Center for High Altitude Medicine, Tibet University Medical College, Lhasa, China.,National Key Laboratory of High Altitude Medicine, Xining, China
| | - Andrew T Lovering
- Department of Human Physiology, University of Oregon, Eugene, OR, United States
| | - Liya Nan
- National Key Laboratory of High Altitude Medicine, Xining, China
| | - Wang Liang Bang
- National Key Laboratory of High Altitude Medicine, Xining, China
| | - Bengt Kayser
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| |
Collapse
|
43
|
Pulmonary Hypertension in Acute and Chronic High Altitude Maladaptation Disorders. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18041692. [PMID: 33578749 PMCID: PMC7916528 DOI: 10.3390/ijerph18041692] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 02/05/2021] [Accepted: 02/07/2021] [Indexed: 12/13/2022]
Abstract
Alveolar hypoxia is the most prominent feature of high altitude environment with well-known consequences for the cardio-pulmonary system, including development of pulmonary hypertension. Pulmonary hypertension due to an exaggerated hypoxic pulmonary vasoconstriction contributes to high altitude pulmonary edema (HAPE), a life-threatening disorder, occurring at high altitudes in non-acclimatized healthy individuals. Despite a strong physiologic rationale for using vasodilators for prevention and treatment of HAPE, no systematic studies of their efficacy have been conducted to date. Calcium-channel blockers are currently recommended for drug prophylaxis in high-risk individuals with a clear history of recurrent HAPE based on the extensive clinical experience with nifedipine in HAPE prevention in susceptible individuals. Chronic exposure to hypoxia induces pulmonary vascular remodeling and development of pulmonary hypertension, which places an increased pressure load on the right ventricle leading to right heart failure. Further, pulmonary hypertension along with excessive erythrocytosis may complicate chronic mountain sickness, another high altitude maladaptation disorder. Importantly, other causes than hypoxia may potentially underlie and/or contribute to pulmonary hypertension at high altitude, such as chronic heart and lung diseases, thrombotic or embolic diseases. Extensive clinical experience with drugs in patients with pulmonary arterial hypertension suggests their potential for treatment of high altitude pulmonary hypertension. Small studies have demonstrated their efficacy in reducing pulmonary artery pressure in high altitude residents. However, no drugs have been approved to date for the therapy of chronic high altitude pulmonary hypertension. This work provides a literature review on the role of pulmonary hypertension in the pathogenesis of acute and chronic high altitude maladaptation disorders and summarizes current knowledge regarding potential treatment options.
Collapse
|
44
|
Huang H, Xie S, Gu X, Xiang B, Zhong Z, Huang P, Gao Y, Li P. Higher Circulating miR-199a-5p Indicates Poor Aerobic Exercise Capacity and Associates With Cardiovascular Dysfunction During Chronic Exposure to High Altitude. Front Physiol 2021; 12:587241. [PMID: 33633582 PMCID: PMC7900411 DOI: 10.3389/fphys.2021.587241] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Accepted: 01/07/2021] [Indexed: 12/14/2022] Open
Abstract
Background Hypoxia-induced decline in exercise capacity is ubiquitous among lowlanders who immigrated to high altitudes, which severely reduces their work efficiency and quality of life. Although studies have revealed that hypoxia-induced cardiovascular dysfunction limits exercise capacity at high altitudes, the mechanisms have not been well explored at the molecular level. miR-199a-5p is hypoxia-sensitive and serves as an important regulator in cardiovascular pathophysiology. However, whether miR-199a-5p is involved in cardiovascular dysfunction at high altitudes and contributes to subsequent reductions in exercise capacity remains unknown. Thus, this study aimed at exploring these relationships in a high altitude population. Methods A total of 175 lowlanders who had immigrated to an altitude of 3,800 m 2 years previously participated in the present study. The level of plasma miR-199a-5p and the concentration of serum myocardial enzymes were detected by qRT-PCR and ELISA, respectively. Indices of cardiovascular function were examined by echocardiography. The exercise capacity was evaluated by Cooper’s 12-min run test and the Harvard Step Test. Furthermore, we explored the biological functions of miR-199a-5p with silico analysis and a biochemical test. Results The level of miR-199a-5p was significantly higher in individuals with poor exercise capacity at 3,800 m, compared with those with good exercise capacity (p < 0.001). miR-199a-5p accurately identified individuals with poor exercise capacity (AUC = 0.752, p < 0.001). The level of miR-199a-5p was positively correlated with cardiovascular dysfunction indices (all, p < 0.001). Furthermore, miR-199a-5p was involved in the oxidative stress process. Conclusion In this study, we reported for the first time that the level of circulating miR-199a-5p was positively associated with exercise capacity during chronic hypoxia at high altitudes. Moreover, higher miR-199a-5p was involved in hypoxia-induced cardiovascular dysfunctions, thus contributing to poorer exercise endurance at high altitudes.
Collapse
Affiliation(s)
- He Huang
- Department of High Altitude Operational Medicine, College of High Altitude Military Medicine, Army Medical University (Third Military Medical University), Chongqing, China.,College of High Altitude Military Medicine, Institute of Medicine and Equipment for High Altitude Region, Army Medical University (Third Military Medical University), Chongqing, China.,Key Laboratory of Extreme Environmental Medicine, Ministry of Education of China, Chongqing, China.,Key Laboratory of High Altitude Medicine, PLA, Chongqing, China
| | - Shenwei Xie
- Shigatse Branch, Second Affiliated Hospital (Xinqiao Hospital) of Army Medical University (Third Military Medical University), Tibet, China
| | - Xiaolan Gu
- Department of Infectious Diseases, First Affiliated Hospital of Army Medical University (Third Military Medical University), Chongqing, China
| | - Bin Xiang
- Department of High Altitude Operational Medicine, College of High Altitude Military Medicine, Army Medical University (Third Military Medical University), Chongqing, China.,Key Laboratory of Extreme Environmental Medicine, Ministry of Education of China, Chongqing, China.,Key Laboratory of High Altitude Medicine, PLA, Chongqing, China
| | - Zhifeng Zhong
- Department of High Altitude Operational Medicine, College of High Altitude Military Medicine, Army Medical University (Third Military Medical University), Chongqing, China.,Key Laboratory of Extreme Environmental Medicine, Ministry of Education of China, Chongqing, China.,Key Laboratory of High Altitude Medicine, PLA, Chongqing, China
| | - Pei Huang
- Department of High Altitude Operational Medicine, College of High Altitude Military Medicine, Army Medical University (Third Military Medical University), Chongqing, China.,Key Laboratory of Extreme Environmental Medicine, Ministry of Education of China, Chongqing, China.,Key Laboratory of High Altitude Medicine, PLA, Chongqing, China
| | - Yuqi Gao
- College of High Altitude Military Medicine, Institute of Medicine and Equipment for High Altitude Region, Army Medical University (Third Military Medical University), Chongqing, China.,Key Laboratory of Extreme Environmental Medicine, Ministry of Education of China, Chongqing, China.,Key Laboratory of High Altitude Medicine, PLA, Chongqing, China
| | - Peng Li
- Department of High Altitude Operational Medicine, College of High Altitude Military Medicine, Army Medical University (Third Military Medical University), Chongqing, China.,Key Laboratory of Extreme Environmental Medicine, Ministry of Education of China, Chongqing, China.,Key Laboratory of High Altitude Medicine, PLA, Chongqing, China
| |
Collapse
|
45
|
Richalet JP. [Adaption to chronic hypoxaemia by populations living at high altitude]. Rev Mal Respir 2021; 38:395-403. [PMID: 33541755 DOI: 10.1016/j.rmr.2020.11.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Accepted: 10/13/2020] [Indexed: 12/14/2022]
Abstract
Permanent life at high altitude induces important physiological stresses linked to the exposure to chronic hypoxia. Various strategies have been adopted by diverse populations living in the Andes, Tibet or East Africa. The main mechanism is an increase in red blood cell production, more marked in Andeans than in Tibetans or Ethiopians. Other changes are observed in the cardiovascular or respiratory systems, as well as in the utero-placental circulation. Sometimes, a de-adaptation process to hypoxia develops, when erythrocytosis becomes excessive and leads to haematological, vascular and cerebral complications (Monge's disease or chronic mountain sickness). Pulmonary hypertension may also appear. Therapeutic options are available but not sufficiently used. Genetic studies have recently been undertaken to try to better understand the evolution of the human genome in populations living in various high altitude regions of the world, as well as the genetic risk factors for chronic diseases. A new model has appeared, intermittent chronic hypoxia, due to the development of economic activities (mainly mining) in desert regions of the Altiplano.
Collapse
Affiliation(s)
- J-P Richalet
- Laboratoire « Hypoxie & Poumon », UMR Inserm U1272, Université Sorbonne Paris Nord 13, 74, rue Marcel-Cachin, 93017 Bobigny cedex, France.
| |
Collapse
|
46
|
Genome-wide comparative analyses reveal selection signatures underlying adaptation and production in Tibetan and Poll Dorset sheep. Sci Rep 2021; 11:2466. [PMID: 33510350 PMCID: PMC7844035 DOI: 10.1038/s41598-021-81932-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 01/11/2021] [Indexed: 12/14/2022] Open
Abstract
The identification of genome-wide selection signatures can provide insights on the mechanisms of natural and/or artificial selection and uncover genes related to biological functions and/or phenotypes. Tibetan sheep are an important livestock in Tibet, providing meat and wool for Tibetans who are renown for breeding livestock that adapt well to high altitudes. Using whole-genome sequences with an effective sequencing depth of 5×, we investigated the genomic diversity and structure and, identified selection signatures of White Tibetan, Oula and Poll Dorset sheep. We obtained 30,163,679 Single Nucleotide Polymorphisms (SNPs) and 5,388,372 indels benchmarked against the ovine Oar_v4.0 genome assembly. Next, using FST, ZHp and XP-EHH approaches, we identified selection signatures spanning a set of candidate genes, including HIF1A, CAPN3, PRKAA1, RXFP2, TRHR and HOXA10 that are associated with pathways and GO categories putatively related to hypoxia responses, meat traits and disease resistance. Candidate genes and GO terms associated with coat color were also identified. Finally, quantification of blood physiological parameters, revealed higher levels of mean corpuscular hemoglobin measurement and mean corpuscular hemoglobin concentration in Tibetan sheep compared with Poll Dorset, suggesting a greater oxygen-carrying capacity in the Tibetan sheep and thus better adaptation to high-altitude hypoxia. In conclusion, this study provides a greater understanding of genome diversity and variations associated with adaptive and production traits in sheep.
Collapse
|
47
|
Arima H, Nakano M, Koirala S, Ito H, Pandey BD, Pandey K, Wada T, Yamamoto T. Unique hemoglobin dynamics in female Tibetan highlanders. Trop Med Health 2021; 49:2. [PMID: 33397517 PMCID: PMC7780399 DOI: 10.1186/s41182-020-00289-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Accepted: 12/07/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Tibetan highlanders have adapted to hypoxic environments through the development of unique mechanisms that suppress an increase in hemoglobin (Hb) concentration even in high-altitude areas. Hb concentrations generally decrease with increasing age. However, in the highlands, chronic altitude sickness is known to occur in the elderly population. To investigate how aging in a hypoxic environment affects Hb levels in Tibetan highlanders, we focused on the Mustang people, who live above 3500 m. We tried to clarify the pure relationship between aging and Hb levels in a hypoxic environment. RESULTS We found that the Hb concentration increased with increasing age in females but not in males. Multivariate analysis showed that age, pulse pressure, the poverty index, and vascular diameter were strongly correlated with the Hb concentration. CONCLUSIONS We found unique Hb dynamics among female Tibetan highlanders. As seen in these Hb dynamics, there may be sex-based differences in the adaptive mechanism in Tibetan highlanders.
Collapse
Affiliation(s)
- Hiroaki Arima
- Department of International Health and Medical Anthropology, Institute of Tropical Medicine, Nagasaki University, 1-12-4 Sakamoto, Nagasaki, 852-8523, Japan.,Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan
| | - Masayuki Nakano
- Department of Nutrition, Faculty of Health Sciences, Kochi Gakuen University, Kochi, Japan
| | | | - Hiromu Ito
- Department of International Health and Medical Anthropology, Institute of Tropical Medicine, Nagasaki University, 1-12-4 Sakamoto, Nagasaki, 852-8523, Japan
| | - Basu Dev Pandey
- Everest International Clinic and Research Center, Kathmandu, Nepal.,Sukraraj Tropical and Infectious Disease Hospital, Kathmandu, Nepal
| | - Kishor Pandey
- Everest International Clinic and Research Center, Kathmandu, Nepal.,Nepal Academy of Science and Technology, Lalitpur, Nepal
| | - Takayuki Wada
- Department of International Health and Medical Anthropology, Institute of Tropical Medicine, Nagasaki University, 1-12-4 Sakamoto, Nagasaki, 852-8523, Japan.,Graduate School of Human Life Science, Osaka City University, Osaka, Japan
| | - Taro Yamamoto
- Department of International Health and Medical Anthropology, Institute of Tropical Medicine, Nagasaki University, 1-12-4 Sakamoto, Nagasaki, 852-8523, Japan. .,Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan. .,Leading Program, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan.
| |
Collapse
|
48
|
Kooman JP, Stenvinkel P, Shiels PG, Feelisch M, Canaud B, Kotanko P. The oxygen cascade in patients treated with hemodialysis and native high-altitude dwellers: lessons from extreme physiology to benefit patients with end-stage renal disease. Am J Physiol Renal Physiol 2020; 320:F249-F261. [PMID: 33356957 DOI: 10.1152/ajprenal.00540.2020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Patients treated with hemodialysis (HD) repeatedly undergo intradialytic low arterial oxygen saturation and low central venous oxygen saturation, reflecting an imbalance between upper body systemic oxygen supply and demand, which are associated with increased mortality. Abnormalities along the entire oxygen cascade, with impaired diffusive and convective oxygen transport, contribute to the reduced tissue oxygen supply. HD treatment impairs pulmonary gas exchange and reduces ventilatory drive, whereas ultrafiltration can reduce tissue perfusion due to a decline in cardiac output. In addition to these factors, capillary rarefaction and reduced mitochondrial efficacy can further affect the balance between cellular oxygen supply and demand. Whereas it has been convincingly demonstrated that a reduced perfusion of heart and brain during HD contributes to organ damage, the significance of systemic hypoxia remains uncertain, although it may contribute to oxidative stress, systemic inflammation, and accelerated senescence. These abnormalities along the oxygen cascade of patients treated with HD appear to be diametrically opposite to the situation in Tibetan highlanders and Sherpa, whose physiology adapted to the inescapable hypobaric hypoxia of their living environment over many generations. Their adaptation includes pulmonary, vascular, and metabolic alterations with enhanced capillary density, nitric oxide production, and mitochondrial efficacy without oxidative stress. Improving the tissue oxygen supply in patients treated with HD depends primarily on preventing hemodynamic instability by increasing dialysis time/frequency or prescribing cool dialysis. Whether dietary or pharmacological interventions, such as the administration of L-arginine, fermented food, nitrate, nuclear factor erythroid 2-related factor 2 agonists, or prolyl hydroxylase 2 inhibitors, improve clinical outcome in patients treated with HD warrants future research.
Collapse
Affiliation(s)
- Jeroen P Kooman
- Division of Nephrology, Department of Internal Medicine, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Peter Stenvinkel
- Division of Renal Medicine, Department of Clinical Science Technology and Intervention, Karolinska Institutet, Stockholm, Sweden
| | - Paul G Shiels
- Institute of Cancer Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Martin Feelisch
- Clinical and Experimental Sciences and Integrative Physiology and Critical Illness Group, Faculty of Medicine, Southampton General Hospital and Institute for Life Sciences, University of Southampton, Southampton, United Kingdom
| | - Bernard Canaud
- Montpellier University, School of Medicine, Montpellier, France & Global Medical Office, Fresenius Medical Care, Bad Homburg, Germany
| | - Peter Kotanko
- Renal Research Institute, New York, New York.,Icahn School of Medicine at Mount Sinai, New York, New York
| |
Collapse
|
49
|
Simpson LL, Steinback CD, Stembridge M, Moore JP. A sympathetic view of blood pressure control at high altitude: new insights from microneurographic studies. Exp Physiol 2020; 106:377-384. [PMID: 33345334 PMCID: PMC7898382 DOI: 10.1113/ep089194] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Accepted: 12/09/2020] [Indexed: 02/06/2023]
Abstract
NEW FINDINGS What is the topic of the review? Sympathoexcitation and sympathetic control of blood pressure at high altitude. What advances does it highlight? Sustained sympathoexcitation is fundamental to integrative control of blood pressure in humans exposed to chronic hypoxia. The largest gaps in current knowledge are in understanding the complex mechanisms by which central sympathetic outflow is regulated at high altitude. ABSTRACT High altitude (HA) hypoxia is a potent activator of the sympathetic nervous system, eliciting increases in sympathetic vasomotor activity. Microneurographic evidence of HA sympathoexcitation dates back to the late 20th century, yet only recently have the characteristics and underpinning mechanisms been explored in detail. This review summarises recent findings and highlights the importance of HA sympathoexcitation for the regulation of blood pressure in lowlanders and indigenous highlanders. In addition, this review identifies gaps in our knowledge and corresponding avenues for future study.
Collapse
Affiliation(s)
- Lydia L Simpson
- Institute for Sport Science, Division of Physiology, Innsbruck University, Innsbruck, Austria
| | - Craig D Steinback
- Neurovascular Health Laboratory, Faculty of Kinesiology, Sport, and Recreation, University of Alberta, Edmonton, Canada
| | - Mike Stembridge
- Cardiff School of Sport and Health Sciences, Cardiff Metropolitan University, Cardiff, UK
| | - Jonathan P Moore
- Extremes Research Group, School of Sport, Health and Exercise Sciences, Bangor University, Bangor, UK
| |
Collapse
|
50
|
Beet on Alps: Time-course changes of plasma nitrate and nitrite concentrations during acclimatization to high-altitude. Nitric Oxide 2020; 107:66-72. [PMID: 33346127 DOI: 10.1016/j.niox.2020.12.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 12/03/2020] [Accepted: 12/14/2020] [Indexed: 11/21/2022]
Abstract
Nitric oxide seems to be involved in the altitude acclimatization process due to its ability to regulate pulmonary, cardiovascular and muscular responses to hypoxia. In this study, we investigated the plasma nitrate (NO3-) and nitrite (NO2-) response to hypobaric hypoxia in two groups of lowlanders exposed at different altitudes. For seven days, fourteen subjects were evaluated at Casati Hut (3269 m a.s.l. M.CEVEDALE) and eleven individuals were studied at Capanna Regina Margherita (4554 m a.s.l. M.ROSA). Before expeditions and at different time points during high-altitude sojourn, plasma NO3- and NO2- concentrations were measured by chemiluminescence. Resting peripheral arterial oxygen saturation (SpO2), heart rate (HR) and mean arterial blood pressure (MAP) were monitored during the experimental period. Possible confounding factors such as dietary NO3- intake, physical activity and altitude changes were controlled. Sea level plasma NO3- and NO2- concentrations significantly increased at altitude in both M.CEVEDALE group (+26.2 μM, p ≤ 0.0001, 95% CI [+17.6, +34.8] and +559.2 nM, p ≤ 0.0001, [+332.8, +785.6]) and M.ROSA group (+18.7 μM, p ≤ 0.0001, [+10.8, +26.5] and +463.7 nM, p ≤ 0.0001, [+314.3, +613.0]). Average peak value in NO metabolites concentration occurred earlier in M.CEVEDALE group vs M.ROSA group (NO3-, day 3 vs day 5, p = 0.007; NO2-, day 3 vs day 5, p = 0.019). In both groups, resting SpO2, HR and MAP values changed according to altitude levels. This study shows that exposure to hypobaric hypoxia affects nitric oxide metabolites, resulting in a significant increase in plasma NO3- and NO2- concentrations from sea level values. Interestingly, the higher the altitude reached, the longer the time taken to reach a peak in plasma concentrations of nitric oxide metabolites.
Collapse
|