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Xin Y, Wang Y, Wang H, Tang X, Bai Y, Lu S, Xin Y. The response of nitric oxide system to high Altitude in Phrynocephalus erythrurus on Qinghai-Tibetan plateau. Comp Biochem Physiol B Biochem Mol Biol 2019; 230:29-36. [PMID: 30690199 DOI: 10.1016/j.cbpb.2019.01.009] [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: 10/23/2018] [Revised: 01/15/2019] [Accepted: 01/18/2019] [Indexed: 11/24/2022]
Abstract
Nitric oxide (NO), produced by nitric oxide synthases (NOS) from L-arginine, plays important roles in a wide range of physiological processes. However, little is known about ectothermic species. To investigate the response of NO/NOS system in adaptation to different altitudes in Phrynocephalus genus, the red tail toad-headed lizard Phrynocephalus erythrurus that live at 4500-5300 m on the Qinghai-Tibet Plateau and another low altitude living lizard Phrynocephalus przewalskii were selected in the present study. The results of mRNA expression and activity of NOSs, as well as NO metabolite levels in different tissues of the two lizards indicate that nNOS mRNA levels in cardiac and skeletal muscle were notably elevated in P. erythrurus, and iNOS expression was also increased markedly (up to 4-fold) in cardiac muscle. There was no significant difference in eNOS mRNA level in tested tissues between two species. However, the total NOS activity in skeletal muscle of P. erythrurus was slightly lower than that of P. przewalskii (p < .05) while no difference in other tissues. Similarly, lower iNOS activity (p < .01) was found in cardiac and skeletal muscle in P. erythrurus compared to P. przewalskii. In addition, the NO metabolite levels were dramatically lower in P. erythrurus in all tested tissues. We propose that higher nNOS and iNOS mRNA expression, lower iNOS activity and NO metabolite levels may represent physiological characteristics in nitric oxide system, which may contribute to high-altitude adaptation in P. erythrurus.
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Affiliation(s)
- Ying Xin
- Medical College of Northwest Minzu University, Lanzhou, China
| | - Yan Wang
- School of Public Health and Management, Ningxia Medical University, Yinchuan, China
| | - Huihui Wang
- Institute of Biochemistry and Molecular Biology, School of Life Science, Lanzhou University, Lanzhou, China
| | - Xiaolong Tang
- Institute of Biochemistry and Molecular Biology, School of Life Science, Lanzhou University, Lanzhou, China
| | - Yucheng Bai
- The No. 1 Middle School of Gannan State, Hezuo City, China
| | - Songsong Lu
- Faculty of Forestry, Gansu Agricultural University, Lanzhou, China
| | - Ying Xin
- Medical College of Northwest Minzu University, Lanzhou, China.
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Reyes RV, Díaz M, Ebensperger G, Herrera EA, Quezada SA, Hernandez I, Sanhueza EM, Parer JT, Giussani DA, Llanos AJ. The role of nitric oxide in the cardiopulmonary response to hypoxia in highland and lowland newborn llamas. J Physiol 2018; 596:5907-5923. [PMID: 29369354 PMCID: PMC6265547 DOI: 10.1113/jp274340] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Accepted: 01/17/2018] [Indexed: 01/19/2023] Open
Abstract
KEY POINTS Perinatal hypoxia causes pulmonary hypertension in neonates, including humans. However, in species adapted to hypoxia, such as the llama, there is protection against pulmonary hypertension. Nitric oxide (NO) is a vasodilatator with an established role in the cardiopulmonary system of many species, but its function in the hypoxic pulmonary vasoconstrictor response in the newborn llama is unknown. Therefore, we studied the role of NO in the cardiopulmonary responses to acute hypoxia in high- and lowland newborn llamas. We show that high- compared to lowland newborn llamas have a reduced pulmonary vasoconstrictor response to acute hypoxia. Protection against excessive pulmonary vasoconstriction in the highland llama is mediated via enhancement of NO pathways, including increased MYPT1 and reduced ROCK expression as well as Ca2+ desensitization. Blunting of pulmonary hypertensive responses to hypoxia through enhanced NO pathways may be an adaptive mechanism to withstand life at high altitude in the newborn llama. ABSTRACT Llamas are born in the Alto Andino with protection against pulmonary hypertension. The physiology underlying protection against pulmonary vasoconstrictor responses to acute hypoxia in highland species is unknown. We determined the role of nitric oxide (NO) in the cardiopulmonary responses to acute hypoxia in high- and lowland newborn llamas. The cardiopulmonary function of newborn llamas born at low (580 m) or high altitude (3600 m) was studied under acute hypoxia, with and without NO blockade. In pulmonary arteries, we measured the reactivity to potassium and sodium nitroprusside (SNP), and in lung we determined the content of cGMP and the expression of the NO-related proteins: BKCa, PDE5, PSer92-PDE5, PKG-1, ROCK1 and 2, MYPT1, PSer695-MYPT1, PThr696-MYPT1, MLC20 and PSer19-MLC20. Pulmonary vascular remodelling was evaluated by morphometry and based on α-actin expression. High- compared to lowland newborn llamas showed lower in vivo pulmonary arterial pressor responses to acute hypoxia. This protection involved enhanced NO function, as NO blockade reverted the effect and the pulmonary arterial dilatator response to SNP was significantly enhanced in highland neonates. The pulmonary expression of ROCK2 and the phosphorylation of MLC20 were lower in high-altitude llamas. Conversely, MYPT1 was up-regulated whilst PSer695-MYPT1 and PThr695-MYPT1 did not change. Enhanced NO-dependent mechanisms were insufficient to prevent pulmonary arterial remodelling. Combined, the data strongly support that in the highland newborn llama reduced ROCK, increased MYPT1 expression and Ca2+ desensitization in pulmonary tissue allow an enhanced NO biology to limit hypoxic pulmonary constrictor responses. Blunting of hypoxic pulmonary hypertensive responses may be an adaptive mechanism to life at high altitude.
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Affiliation(s)
- Roberto V. Reyes
- Laboratorio de Bioquímica y Biología Molecular de la Hipoxia, Programa de Fisiopatología, Instituto de Ciencias Biomédicas, Facultad de MedicinaUniversidad de ChileSantiagoChile
- International Center for Andean Studies (INCAS)Universidad de ChileSantiagoChile
| | - Marcela Díaz
- Departamento de Promoción de la Salud de la Mujer y el Recién Nacido, Facultad de MedicinaUniversidad de ChileSantiagoChile
- Laboratorio de Mecanismos de Stress y Adaptación Vascular, Programa de Fisiopatología, Instituto de Ciencias Biomédicas, Facultad de MedicinaUniversidad de ChileSantiagoChile
| | - Germán Ebensperger
- Laboratorio de Mecanismos de Stress y Adaptación Vascular, Programa de Fisiopatología, Instituto de Ciencias Biomédicas, Facultad de MedicinaUniversidad de ChileSantiagoChile
| | - Emilio A. Herrera
- International Center for Andean Studies (INCAS)Universidad de ChileSantiagoChile
- Laboratorio de Función y Reactividad Vascular, Programa de Fisiopatología, Instituto de Ciencias Biomédicas, Facultad de MedicinaUniversidad de ChileSantiagoChile
| | - Sebastián A. Quezada
- Laboratorio de Bioquímica y Biología Molecular de la Hipoxia, Programa de Fisiopatología, Instituto de Ciencias Biomédicas, Facultad de MedicinaUniversidad de ChileSantiagoChile
| | - Ismael Hernandez
- Laboratorio de Bioquímica y Biología Molecular de la Hipoxia, Programa de Fisiopatología, Instituto de Ciencias Biomédicas, Facultad de MedicinaUniversidad de ChileSantiagoChile
| | - Emilia M. Sanhueza
- Laboratorio de Fisiología y Fisiopatología del Desarrollo, Programa de Fisiopatología, Instituto de Ciencias Biomédicas, Facultad de MedicinaUniversidad de ChileSantiagoChile
| | - Julian T. Parer
- Department of Obstetrics, Gynecology and Reproductive SciencesUniversity of California San FranciscoCaliforniaUSA
| | - Dino A. Giussani
- Department of Physiology, Development and NeuroscienceUniversity of CambridgeUK
| | - Aníbal J. Llanos
- International Center for Andean Studies (INCAS)Universidad de ChileSantiagoChile
- Laboratorio de Fisiología y Fisiopatología del Desarrollo, Programa de Fisiopatología, Instituto de Ciencias Biomédicas, Facultad de MedicinaUniversidad de ChileSantiagoChile
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Summerfield DT, Coffman KE, Taylor BJ, Issa AN, Johnson BD. Exhaled Nitric Oxide Changes During Acclimatization to High Altitude: A Descriptive Study. High Alt Med Biol 2018; 19:215-220. [PMID: 29757001 DOI: 10.1089/ham.2017.0109] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Summerfield, Douglas T., Kirsten E. Coffman, Bryan J. Taylor, Amine N. Issa, and Bruce D. Johnson. Exhaled nitric oxide changes during acclimatization to high altitude: a descriptive study. High Alt Med Biol. 19:215-220, 2018. AIMS This study describes differences in the partial pressures of exhaled nitric oxide (PeNO) between subjects fully acclimatized (ACC) to 5300 m and those who have just arrived to high altitude. METHODS PeNO was determined in eight subjects newly exposed and nonacclimatized (non-ACC) to high altitude and compared with that in nine subjects who had ACC to high altitude for 1 month. In addition, systolic pulmonary artery pressure (sPAP) and arterial oxygen saturation (SaO2) were measured in all participants. These measurements were repeated in the non-ACC group 5 and 9 days later. RESULTS PeNO levels on day 1 were significantly higher in the non-ACC versus ACC cohort (8.7 ± 3.5 vs. 3.9 ± 2.2 nmHg, p = 0.004). As the non-ACC group remained at altitude, PeNO levels fell and were not different when compared with those of the ACC group by day 9 (5.9 ± 2.4 vs. 3.9 ± 2.2 nmHg, p = 0.095). Higher sPAP was correlated with lower PeNO levels in all participants (R = -0.50, p = 0.043). PeNO levels were not correlated with SaO2. CONCLUSIONS As individuals acclimatized to high altitude, PeNO levels decreased. Even after acclimatization, PeNO levels continued to play a role in pulmonary vascular tone.
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Affiliation(s)
| | - Kirsten E Coffman
- 2 Mayo Clinic Graduate School of Biomedical Sciences , Mayo Clinic, Rochester, Minnesota
| | - Bryan J Taylor
- 3 School of Biomedical Sciences, University of Leeds , Leeds, United Kingdom
| | - Amine N Issa
- 4 Department of Cardiovascular Diseases, Mayo Clinic , Rochester, Minnesota
| | - Bruce D Johnson
- 4 Department of Cardiovascular Diseases, Mayo Clinic , Rochester, Minnesota
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Wang D, Wang Y, Liang H, David JE, Bray CL. Race and ethnicity have significant influence on fractional exhaled nitric oxide. Ann Allergy Asthma Immunol 2018; 120:272-277.e1. [PMID: 29398244 DOI: 10.1016/j.anai.2017.11.021] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Revised: 11/10/2017] [Accepted: 11/27/2017] [Indexed: 01/09/2023]
Abstract
BACKGROUND Race and ethnicity have been shown to influence fractional exhaled nitric oxide (FeNO). There is a need to investigate cutoff points for different races and ethnicities to improve clinical application. OBJECTIVE To investigate cutoff points for different races and ethnicities by analyzing the FeNO data collected by the National Health and Nutrition Examination Survey from 2007 to 2012. METHODS This study included 23,433 participants. After excluding participants with confounding factors, 11,084 participants were eligible for data analysis. Based on age and the probability of having allergic airway inflammation, participants were divided into 4 groups. The geometric mean and 5th, 50th, and 95th percentiles of FeNO in Hispanic, white, black, and other races were analyzed in all groups. RESULTS Compared with white participants, the geometric mean for FeNO in black participants was 36% to 41% higher in children and 5% to 8% higher in adults. Hispanic children had significantly higher FeNO values (14% to 19%) compared with non-Hispanic white children; however, those differences were not significant in adults. Other races had significantly higher FeNO values in children (24-54%) and adults (9-29%) compared with white participants. Further, for normal healthy black children, the 95th percentile was 40.2 parts per billion (ppb), which is significantly higher than the cutoff point recommended by current guidelines. CONCLUSION Although there are significant differences in FeNO values among races and ethnicities, the current cutoff point at 50 ppb is sufficient to separate healthy from asthmatic populations in adults. However, for black children, we suggest increasing the cutoff point from 35 to 40 ppb to avoid unnecessary diagnosis and treatment.
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Affiliation(s)
- Dong Wang
- University of Central Florida, College of Medicine, Hospital Corporation of American Graduate Medical Education Program in Internal Medicine at North Florida Regional Medical Center, Gainesville, Florida.
| | - Yanning Wang
- University of Central Florida, College of Medicine, Hospital Corporation of American Graduate Medical Education Program in Internal Medicine at North Florida Regional Medical Center, Gainesville, Florida
| | - Hong Liang
- University of Central Florida, College of Medicine, Hospital Corporation of American Graduate Medical Education Program in Internal Medicine at North Florida Regional Medical Center, Gainesville, Florida
| | - John E David
- University of Central Florida, College of Medicine, Hospital Corporation of American Graduate Medical Education Program in Internal Medicine at North Florida Regional Medical Center, Gainesville, Florida
| | - Christopher L Bray
- University of Central Florida, College of Medicine, Hospital Corporation of American Graduate Medical Education Program in Internal Medicine at North Florida Regional Medical Center, Gainesville, Florida
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Moore LG. Measuring high-altitude adaptation. J Appl Physiol (1985) 2017; 123:1371-1385. [PMID: 28860167 DOI: 10.1152/japplphysiol.00321.2017] [Citation(s) in RCA: 113] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Revised: 08/15/2017] [Accepted: 08/15/2017] [Indexed: 12/12/2022] Open
Abstract
High altitudes (>8,000 ft or 2,500 m) provide an experiment of nature for measuring adaptation and the physiological processes involved. Studies conducted over the past ~25 years in Andeans, Tibetans, and, less often, Ethiopians show varied but distinct O2 transport traits from those of acclimatized newcomers, providing indirect evidence for genetic adaptation to high altitude. Short-term (acclimatization, developmental) and long-term (genetic) responses to high altitude exhibit a temporal gradient such that, although all influence O2 content, the latter also improve O2 delivery and metabolism. Much has been learned concerning the underlying physiological processes, but additional studies are needed on the regulation of blood flow and O2 utilization. Direct evidence of genetic adaptation comes from single-nucleotide polymorphism (SNP)-based genome scans and whole genome sequencing studies that have identified gene regions acted upon by natural selection. Efforts have begun to understand the connections between the two with Andean studies on the genetic factors raising uterine blood flow, fetal growth, and susceptibility to Chronic Mountain Sickness and Tibetan studies on genes serving to lower hemoglobin and pulmonary arterial pressure. Critical for future studies will be the selection of phenotypes with demonstrable effects on reproductive success, the calculation of actual fitness costs, and greater inclusion of women among the subjects being studied. The well-characterized nature of the O2 transport system, the presence of multiple long-resident populations, and relevance for understanding hypoxic disorders in all persons underscore the importance of understanding how evolutionary adaptation to high altitude has occurred.NEW & NOTEWORTHY Variation in O2 transport characteristics among Andean, Tibetan, and, when available, Ethiopian high-altitude residents supports the existence of genetic adaptations that improve the distribution of blood flow to vital organs and the efficiency of O2 utilization. Genome scans and whole genome sequencing studies implicate a broad range of gene regions. Future studies are needed using phenotypes of clear relevance for reproductive success for determining the mechanisms by which naturally selected genes are acting.
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Affiliation(s)
- Lorna G Moore
- Division of Reproductive Sciences, Department of Obstetrics & Gynecology, University of Colorado Denver-Anschutz Medical Campus, Aurora, Colorado
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Sheak JR, Weise-Cross L, deKay RJ, Walker BR, Jernigan NL, Resta TC. Enhanced NO-dependent pulmonary vasodilation limits increased vasoconstrictor sensitivity in neonatal chronic hypoxia. Am J Physiol Heart Circ Physiol 2017; 313:H828-H838. [PMID: 28733445 DOI: 10.1152/ajpheart.00123.2017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Revised: 07/17/2017] [Accepted: 07/17/2017] [Indexed: 02/03/2023]
Abstract
Augmented vasoconstrictor reactivity is thought to play an important role in the development of chronic hypoxia (CH)-induced neonatal pulmonary hypertension. However, whether this response to CH results from pulmonary endothelial dysfunction and reduced nitric oxide (NO)-mediated vasodilation is not well understood. We hypothesized that neonatal CH enhances basal tone and pulmonary vasoconstrictor sensitivity by limiting NO-dependent pulmonary vasodilation. To test this hypothesis, we assessed the effects of the NO synthase (NOS) inhibitor Nω-nitro-l-arginine (l-NNA) on baseline pulmonary vascular resistance (PVR) and vasoconstrictor sensitivity to the thromboxane mimetic U-46619 in saline-perfused lungs (in situ) from 2-wk-old control and CH (12-day exposure, 0.5 atm) Sprague-Dawley rats. Basal tone was defined as that reversed by exogenous NO (spermine NONOate). CH neonates displayed elevated right ventricular systolic pressure (in vivo) and right ventricular hypertrophy, indicative of pulmonary hypertension. Perfused lungs from CH rats demonstrated greater baseline PVR, basal tone, and U-46619-mediated vasoconstriction compared with control rats in the absence of l-NNA. l-NNA markedly increased baseline PVR and reactivity to U-46619 in lungs from CH neonates, further augmenting vasoconstrictor sensitivity compared with control lungs. Exposure to CH also enhanced NO-dependent vasodilation to arginine vasopressin, pulmonary expression of NOS III [endothelial NOS (eNOS)], and eNOS phosphorylation at activation residue Ser1177 However, CH did not alter lung nitrotyrosine levels, a posttranslational modification reflecting [Formula: see text] scavenging of NO. We conclude that, in contrast to our hypothesis, enhanced basal tone and agonist-induced vasoconstriction after neonatal CH is limited by increased NO-dependent pulmonary vasodilation resulting from greater eNOS expression and phosphorylation at activation residue Ser1177NEW & NOTEWORTHY This research is the first to demonstrate enhanced nitric oxide-dependent vasodilation that limits increased vasoconstrictor reactivity in neonatal pulmonary hypertension. These results suggest that augmented vasoconstriction in this setting reflects changes in smooth muscle reactivity rather than a reduction in nitric oxide-dependent pulmonary vasodilation.
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Affiliation(s)
- Joshua R Sheak
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico
| | - Laura Weise-Cross
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico
| | - Ray J deKay
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico
| | - Benjimen R Walker
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico
| | - Nikki L Jernigan
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico
| | - Thomas C Resta
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico
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