1
|
Sun M, Li Q, Zou Z, Liu J, Gu Z, Li L. The mechanisms behind heatstroke-induced intestinal damage. Cell Death Discov 2024; 10:455. [PMID: 39468029 DOI: 10.1038/s41420-024-02210-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2024] [Revised: 10/04/2024] [Accepted: 10/10/2024] [Indexed: 10/30/2024] Open
Abstract
With the frequent occurrence of heatwaves, heatstroke (HS) is expected to become one of the main causes of global death. Being a multi-organized disease, HS can result in circulatory disturbance and systemic inflammatory response, with the gastrointestinal tract being one of the primary organs affected. Intestinal damage plays an initiating and promoting role in HS. Multiple pathways result in damage to the integrity of the intestinal epithelial barrier due to heat stress and hypoxia brought on by blood distribution. This usually leads to intestinal leakage as well as the infiltration and metastasis of toxins and pathogenic bacteria in the intestinal cavity, which will eventually cause inflammation in the whole body. A large number of studies have shown that intestinal damage after HS involves the body's stress response, disruption of oxidative balance, disorder of tight junction proteins, massive cell death, and microbial imbalance. Based on these damage mechanisms, protecting the intestinal barrier and regulating the body's inflammatory and immune responses are effective treatment strategies. To better understand the pathophysiology of this complex process, this review aims to outline the potential processes and possible therapeutic strategies for intestinal damage after HS in recent years.
Collapse
Affiliation(s)
- Minshu Sun
- Department of Treatment Center For Traumatic Injuries, The Third Affiliated Hospital of Southern Medical University, Guangzhou, Guangdong, China
- Academy of Orthopedics·Guangdong Province, Orthopedic Hospital of Guangdong Province, Guangdong Provincial Key Laboratory of Bone and Joint Degenerative Diseases, The Third Affiliated Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Qin Li
- Department of Treatment Center For Traumatic Injuries, The Third Affiliated Hospital of Southern Medical University, Guangzhou, Guangdong, China
- Academy of Orthopedics·Guangdong Province, Orthopedic Hospital of Guangdong Province, Guangdong Provincial Key Laboratory of Bone and Joint Degenerative Diseases, The Third Affiliated Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Zhimin Zou
- Department of Treatment Center For Traumatic Injuries, The Third Affiliated Hospital of Southern Medical University, Guangzhou, Guangdong, China
- Academy of Orthopedics·Guangdong Province, Orthopedic Hospital of Guangdong Province, Guangdong Provincial Key Laboratory of Bone and Joint Degenerative Diseases, The Third Affiliated Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Jian Liu
- Department of Treatment Center For Traumatic Injuries, The Third Affiliated Hospital of Southern Medical University, Guangzhou, Guangdong, China
- Academy of Orthopedics·Guangdong Province, Orthopedic Hospital of Guangdong Province, Guangdong Provincial Key Laboratory of Bone and Joint Degenerative Diseases, The Third Affiliated Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Zhengtao Gu
- Department of Treatment Center For Traumatic Injuries, The Third Affiliated Hospital of Southern Medical University, Guangzhou, Guangdong, China.
- Academy of Orthopedics·Guangdong Province, Orthopedic Hospital of Guangdong Province, Guangdong Provincial Key Laboratory of Bone and Joint Degenerative Diseases, The Third Affiliated Hospital, Southern Medical University, Guangzhou, Guangdong, China.
| | - Li Li
- Department of Intensive Care Unit, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China.
| |
Collapse
|
2
|
Rosbrook P, Margolis LM, Pryor JL. Nutritional Considerations in Exercise-Based Heat Acclimation: A Narrative Review. Sports Med 2024:10.1007/s40279-024-02109-x. [PMID: 39217233 DOI: 10.1007/s40279-024-02109-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/15/2024] [Indexed: 09/04/2024]
Abstract
In addition to its established thermoregulatory and cardiovascular effects, heat stress provokes alterations in macronutrient metabolism, gastrointestinal integrity, and appetite. Inadequate energy, carbohydrate, and protein intake have been implicated in reduced exercise and heat tolerance. Classic exercise heat acclimation (HA) protocols employ low-to-moderate-intensity exercise for 5-14 days, while recent studies have evolved the practice by implementing high-intensity and task-specific exercise during HA, which potentially results in impaired post-HA physical performance despite adequate heat adaptations. While there is robust literature demonstrating the performance benefit of various nutritional interventions during intensive training and competition, most HA studies implement few nutritional controls. This review summarizes the relationships between heat stress, HA, and intense exercise in connection with substrate metabolism, gastrointestinal function, and the potential consequences of reduced energy availability. We discuss the potential influence of macronutrient manipulations on HA study outcomes and suggest best practices to implement nutritional controls.
Collapse
Affiliation(s)
- Paul Rosbrook
- Center for Research & Education in Special Environments, Department of Exercise & Nutrition Sciences, State University of New York University at Buffalo, Buffalo, NY, USA.
| | - Lee M Margolis
- Military Nutrition Division, U.S. Army Research Institute for Environmental Medicine, Natick, MA, USA
| | - J Luke Pryor
- Center for Research & Education in Special Environments, Department of Exercise & Nutrition Sciences, State University of New York University at Buffalo, Buffalo, NY, USA
| |
Collapse
|
3
|
Weitz CA. Coping with extreme heat: current exposure and implications for the future. Evol Med Public Health 2024; 12:eoae015. [PMID: 39359409 PMCID: PMC11445678 DOI: 10.1093/emph/eoae015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2024] [Accepted: 07/02/2024] [Indexed: 10/04/2024] Open
Abstract
A preview of how effective behavioral, biological and technological responses might be in the future, when outdoor conditions will be at least 2°C hotter than current levels, is available today from studies of individuals already living in extreme heat. In areas where high temperatures are common-particularly those in the hot and humid tropics-several studies report that indoor temperatures in low-income housing can be significantly hotter than those outdoors. A case study indicates that daily indoor heat indexes in almost all the 123 slum dwellings monitored in Kolkata during the summer were above 41°C (106°F) for at least an hour. Economic constraints make it unlikely that technological fixes, such as air conditioners, will remedy conditions like these-now or in the future. People without access to air conditioning will have to rely on behavioral adjustments and/or biological/physiological acclimatization. One important unknown is whether individuals who have lived their entire lives in hot environments without air conditioning possess natural levels of acclimatization greater than those indicated by controlled laboratory studies. Answering questions about the future will require more studies of heat conditions experienced by individuals, more information on indoor versus outdoor heat conditions, and a greater understanding of the behavioral and biological adjustments made by people living today in extremely hot conditions.
Collapse
Affiliation(s)
- Charles A Weitz
- Department of Anthropology, Temple University, Philadelphia, PA 19122, USA
| |
Collapse
|
4
|
Bennett S, Tiollier E, Owens DJ, Brocherie F, Louis JB. Implications of Heat Stress-induced Metabolic Alterations for Endurance Training. Int J Sports Med 2024; 45:422-435. [PMID: 38401534 DOI: 10.1055/a-2251-3170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/26/2024]
Abstract
Inducing a heat-acclimated phenotype via repeated heat stress improves exercise capacity and reduces athletes̓ risk of hyperthermia and heat illness. Given the increased number of international sporting events hosted in countries with warmer climates, heat acclimation strategies are increasingly popular among endurance athletes to optimize performance in hot environments. At the tissue level, completing endurance exercise under heat stress may augment endurance training adaptation, including mitochondrial and cardiovascular remodeling due to increased perturbations to cellular homeostasis as a consequence of metabolic and cardiovascular load, and this may improve endurance training adaptation and subsequent performance. This review provides an up-to-date overview of the metabolic impact of heat stress during endurance exercise, including proposed underlying mechanisms of altered substrate utilization. Against this metabolic backdrop, the current literature highlighting the role of heat stress in augmenting training adaptation and subsequent endurance performance will be presented with practical implications and opportunities for future research.
Collapse
Affiliation(s)
- Samuel Bennett
- Center for Biological Clocks Research, Texas A&M University, College Station, United States
| | - Eve Tiollier
- Laboratory Sport, Expertise and Performance, Research Department, Institut National du Sport de l'Expertise et de la Performance, Paris, France
| | - Daniel J Owens
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom of Great Britain and Northern Ireland
| | - Franck Brocherie
- Laboratory Sport, Expertise and Performance, Research Department, Institut National du Sport de l'Expertise et de la Performance, Paris, France
| | - Julien B Louis
- Laboratory Sport, Expertise and Performance, Research Department, Institut National du Sport de l'Expertise et de la Performance, Paris, France
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom of Great Britain and Northern Ireland
| |
Collapse
|
5
|
Dunn RA, Luk HY, Appell CR, Jiwan NC, Keefe MS, Rolloque JJS, Sekiguchi Y. Eccentric muscle-damaging exercise in the heat lowers cellular stress prior to and immediately following future exertional heat exposure. Cell Stress Chaperones 2024; 29:472-482. [PMID: 38735625 PMCID: PMC11131061 DOI: 10.1016/j.cstres.2024.05.001] [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: 02/05/2024] [Revised: 04/22/2024] [Accepted: 05/04/2024] [Indexed: 05/14/2024] Open
Abstract
Muscle-damaging exercise (e.g., downhill running [DHR]) or heat exposure bouts potentially reduce physiological and/or cellular stress during future exertional heat exposure; however, the true extent of their combined preconditioning effects is unknown. Therefore, this study investigated the effect of muscle-damaging exercise in the heat on reducing physiological and cellular stress during future exertional heat exposure. Ten healthy males (mean ± Standard Definition; age, 23 ± 3 years; body mass, 78.7 ± 11.5 kg; height, 176.9 ± 4.7 cm) completed this study. Participants were randomly assigned into two preconditioning groups: (a) DHR in the heat (ambient temperature [Tamb], 35 °C; relative humidity [RH], 40%) and (b) DHR in thermoneutral (Tamb, 20 °C; RH, 20%). Seven days following DHR, participants performed a 45-min flat run in the heat (FlatHEAT [Tamb, 35 °C; RH, 40%]). During exercise, heart rate and rectal temperature (Trec) were recorded at baseline and every 5-min. Peripheral blood mononuclear cells were isolated to assess heat shock protein 72 (Hsp72) concentration between conditions at baseline, immediately post-DHR, and immediately pre-FlatHEAT and post-FlatHEAT. Mean Trec during FlatHEAT between hot (38.23 ± 0.38 °C) and thermoneutral DHR (38.26 ± 0.38 °C) was not significantly different (P = 0.68), with no mean heart rate differences during FlatHEAT between hot (172 ± 15 beats min-1) and thermoneutral conditions (174 ± 8 beats min-1; P = 0.58). Hsp72 concentration change from baseline to immediately pre-FlatHEAT was significantly lower in hot (-51.4%) compared to thermoneutral (+24.2%; P = 0.025) DHR, with Hsp72 change from baseline to immediately post-FlatHEAT also lower in hot (-52.6%) compared to thermoneutral conditions (+26.3%; P = 0.047). A bout of muscle-damaging exercise in the heat reduces cellular stress levels prior to and immediately following future exertional heat exposure.
Collapse
Affiliation(s)
- Ryan A Dunn
- Sports Performance Laboratory, Department of Kinesiology and Sport Management, Texas Tech University, Lubbock, TX, USA
| | - Hui-Ying Luk
- Applied Physiology Laboratory, Department of Kinesiology and Sport Management, Texas Tech University, Lubbock, TX, USA
| | - Casey R Appell
- Applied Physiology Laboratory, Department of Kinesiology and Sport Management, Texas Tech University, Lubbock, TX, USA
| | - Nigel C Jiwan
- Applied Physiology Laboratory, Department of Kinesiology and Sport Management, Texas Tech University, Lubbock, TX, USA
| | - Marcos S Keefe
- Sports Performance Laboratory, Department of Kinesiology and Sport Management, Texas Tech University, Lubbock, TX, USA
| | - Jan-Joseph S Rolloque
- Sports Performance Laboratory, Department of Kinesiology and Sport Management, Texas Tech University, Lubbock, TX, USA
| | - Yasuki Sekiguchi
- Sports Performance Laboratory, Department of Kinesiology and Sport Management, Texas Tech University, Lubbock, TX, USA.
| |
Collapse
|
6
|
Janssens L, Asselman J, De Troch M. Effects of ocean warming on the fatty acid and epigenetic profile of Acartia tonsa: A multigenerational approach. MARINE POLLUTION BULLETIN 2024; 201:116265. [PMID: 38493676 DOI: 10.1016/j.marpolbul.2024.116265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 03/07/2024] [Accepted: 03/11/2024] [Indexed: 03/19/2024]
Abstract
The effects of climate change are becoming more prevalent, and it is important to know how copepods, the most abundant class in zooplankton, will react to changing temperatures as they are the main food source for secondary consumers. They act as key transferers of nutrients from primary producers to organisms higher up the food chain. Little is known about the effects of temperature changes on copepods on the long term, i.e., over several generations. Especially the epigenetic domain seems to be understudied and the question remains whether the nutritional value of copepods will permanently change with rising water temperatures. In this research, the effects of temperature on the fatty acid and epigenetic profiles of the abundant planktonic copepod Acartia tonsa were investigated, since we expect to see a link between these two. Indeed, changing methylation patterns helped copepods to deal with higher temperatures, which is in line with the relative abundance of the most important fatty acids, e.g., DHA. However, this pattern was only observed when temperature increased slowly. A sudden increase in temperature showed the opposite effect; Acartia tonsa did not show deviant methylation patterns and the relative abundance of DHA and other important fatty acids dropped significantly after several generations. These results suggest that local fluctuations in temperature have a greater effect on Acartia tonsa than an elevation of the global mean.
Collapse
Affiliation(s)
- Lotte Janssens
- Marine Biology Research Group, Ghent University, Campus Sterre S8, Krijgslaan 281, B-9000 Ghent, Belgium; Blue Growth Research Lab, Ghent University, Bluebridge, Wetenschapspark 1, 8400, Ostend, Belgium.
| | - Jana Asselman
- Blue Growth Research Lab, Ghent University, Bluebridge, Wetenschapspark 1, 8400, Ostend, Belgium
| | - Marleen De Troch
- Marine Biology Research Group, Ghent University, Campus Sterre S8, Krijgslaan 281, B-9000 Ghent, Belgium
| |
Collapse
|
7
|
Notley SR, Mitchell D, Taylor NAS. A century of exercise physiology: concepts that ignited the study of human thermoregulation. Part 4: evolution, thermal adaptation and unsupported theories of thermoregulation. Eur J Appl Physiol 2024; 124:147-218. [PMID: 37796290 DOI: 10.1007/s00421-023-05262-9] [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: 02/06/2023] [Accepted: 06/13/2023] [Indexed: 10/06/2023]
Abstract
This review is the final contribution to a four-part, historical series on human exercise physiology in thermally stressful conditions. The series opened with reminders of the principles governing heat exchange and an overview of our contemporary understanding of thermoregulation (Part 1). We then reviewed the development of physiological measurements (Part 2) used to reveal the autonomic processes at work during heat and cold stresses. Next, we re-examined thermal-stress tolerance and intolerance, and critiqued the indices of thermal stress and strain (Part 3). Herein, we describe the evolutionary steps that endowed humans with a unique potential to tolerate endurance activity in the heat, and we examine how those attributes can be enhanced during thermal adaptation. The first of our ancestors to qualify as an athlete was Homo erectus, who were hairless, sweating specialists with eccrine sweat glands covering almost their entire body surface. Homo sapiens were skilful behavioural thermoregulators, which preserved their resource-wasteful, autonomic thermoeffectors (shivering and sweating) for more stressful encounters. Following emigration, they regularly experienced heat and cold stress, to which they acclimatised and developed less powerful (habituated) effector responses when those stresses were re-encountered. We critique hypotheses that linked thermoregulatory differences to ancestry. By exploring short-term heat and cold acclimation, we reveal sweat hypersecretion and powerful shivering to be protective, transitional stages en route to more complete thermal adaptation (habituation). To conclude this historical series, we examine some of the concepts and hypotheses of thermoregulation during exercise that did not withstand the tests of time.
Collapse
Affiliation(s)
- Sean R Notley
- Defence Science and Technology Group, Department of Defence, Melbourne, Australia
- School of Human Kinetics, University of Ottawa, Ottawa, Canada
| | - Duncan Mitchell
- Brain Function Research Group, School of Physiology, University of the Witwatersrand, Johannesburg, South Africa
- School of Human Sciences, University of Western Australia, Crawley, Australia
| | - Nigel A S Taylor
- Research Institute of Human Ecology, College of Human Ecology, Seoul National University, Seoul, Republic of Korea.
| |
Collapse
|
8
|
Liang JS, Hung KL, Lin LJ, Ong WP, Keng WT, Lu JF. Novel PEX1 mutations in fibroblasts from children with Zellweger spectrum disorders exhibit temperature sensitive characteristics. Epilepsy Behav 2023; 145:109266. [PMID: 37385119 DOI: 10.1016/j.yebeh.2023.109266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 05/12/2023] [Accepted: 05/13/2023] [Indexed: 07/01/2023]
Abstract
Zellweger spectrum disorders (ZSD) are rare autosomal recessive disorders caused by defects in peroxisome biogenesis factor (PEX; peroxin) genes leading to impaired transport of peroxisomal proteins with peroxisomal targeting signals (PTS). Four patients, including a pair of homozygotic twins, diagnosed as ZSD by genetic study with different clinical presentations and outcomes as well as various novel mutations are described here. A total of 3 novel mutations, including a nonsense, a frameshift, and a splicing mutation, in PEX1 from ZSD patients were identified and unequivocally confirmed that the p.Ile989Thr mutant PEX1 exhibited temperature-sensitive characteristics and is associated with milder ZSD. The nature of the p.Ile989Thr mutant exhibited different characteristics from that of the other previously identified temperature-sensitive p.Gly843Asp PEX1 mutant. Transcriptome profiles under nonpermissive vs. permissive conditions were explored to facilitate the understanding of p.Ile989Thr mutant PEX1. Further investigation of molecular mechanisms may help to clarify potential genetic causes that could modify the clinical presentation of ZSD.
Collapse
Affiliation(s)
- Jao-Shwann Liang
- Departments of Pediatrics, Far Eastern Memorial Hospital, New Taipei City, Taiwan; Department of Nursing, Asia Eastern University of Science and Technology, New Taipei City, Taiwan
| | - Kun-Long Hung
- Departments of Pediatrics, Fu Jen Catholic University Hospital, New Taipei City, Taiwan; School of Medicine, Fu Jen Catholic University, New Taipei City, Taiwan
| | - Li-Ju Lin
- School of Medicine, Fu Jen Catholic University, New Taipei City, Taiwan
| | - Winnie Peitee Ong
- Department of Genetics, Kuala Lumpur Hospital, Kuala Lumpur, Malaysia
| | - Wee Teik Keng
- Department of Genetics, Kuala Lumpur Hospital, Kuala Lumpur, Malaysia
| | - Jyh-Feng Lu
- School of Medicine, Fu Jen Catholic University, New Taipei City, Taiwan.
| |
Collapse
|
9
|
Li X, Xv F, Ma LZ, Xing L, Zhao JB, Zhi WJ, Wang LF, Wang Y, Mao HD, Liu SY, Liu YH, Song Q. Acquired heat acclimation in rats subjected to physical exercise under environmental heat stress alleviates brain injury caused by exertional heat stroke. Brain Res 2023; 1811:148393. [PMID: 37150340 DOI: 10.1016/j.brainres.2023.148393] [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: 12/25/2022] [Revised: 05/01/2023] [Accepted: 05/02/2023] [Indexed: 05/09/2023]
Abstract
BACKGROUND Exertional heatstroke (EHS) is an emergency with a high mortality rate, characterized by central nervous system dysfunctions. This study aims to establish a Heat acclimation/acclimatization (HA) rat model in locomotion to recapitulate the physical state of human in severe environment of high temperature and humidity, and investigate the mechanism of organism protection in HA. (2) Methods: Wistar rats were exposed to 36°C and ran 2 h/d for 21 days, acquired thermal tolerance test was conducted to assess the thermotolerance and exercise ability. Core temperature and consumption of water and food were observed. Expression of HSP70 and HSP90 of different tissues were determined by WB. Pathological structure of brain tissue was detected with HE staining. Proteomics was used to identify the differently expressed proteins in cerebral cortex of different groups. And key molecules were identified by RT-PCR and WB. (3) Results: HA rats displayed stronger thermotolerance and exercised ability on acquired thermal tolerance test. Brain water content of HA+EHS group reduced compared with EHS group. HE staining revealed slighter brain injuries of HA+EHS group than that of EHS. Proteomics focused on cell death-related pathways and key molecules Aquaporin 4 (AQP4) related to cell edema. Identification results showed HA increased AQP4, Bcl-xl, ratio of p-Akt/AKT and Bcl-xl/Bax, down-regulated Cleaved Caspase-3. (4) Conclusions: This HA model can ameliorate brain injury of EHS by reducing cerebral edema and cell apoptosis, offering experimental evidence for EHS prophylaxis.
Collapse
Affiliation(s)
- Xin Li
- Postgraduate School, Medical School of Chinese PLA, Beijing 100853, China; Department of Emergency, Third Medical Center of Chinese PLA General Hospital, Beijing 100039, China.
| | - Fan Xv
- Postgraduate School, Medical School of Chinese PLA, Beijing 100853, China.
| | - Li-Zhen Ma
- Beijing Institute of Radiation Medicine, 27 Taiping Road, Beijing 100850, China.
| | - Ling Xing
- Department of Emergency, Beijing Tongren Hospital, Capital Medical University, Beijing. 100176, China.
| | - Jin-Bao Zhao
- Department of Emergency, sixth Medical Center of Chinese PLA General Hospital, Beijing, 100048, China.
| | - Wei-Jia Zhi
- Beijing Institute of Radiation Medicine, 27 Taiping Road, Beijing 100850, China.
| | - Li-Feng Wang
- Beijing Institute of Radiation Medicine, 27 Taiping Road, Beijing 100850, China.
| | - Yang Wang
- Beijing Institute of Radiation Medicine, 27 Taiping Road, Beijing 100850, China.
| | - Han-Ding Mao
- Postgraduate School, Medical School of Chinese PLA, Beijing 100853, China.
| | - Shu-Yuan Liu
- Department of Emergency, sixth Medical Center of Chinese PLA General Hospital, Beijing, 100048, China.
| | - Ya-Hua Liu
- Department of Emergency, Third Medical Center of Chinese PLA General Hospital, Beijing 100039, China.
| | - Qing Song
- Postgraduate School, Medical School of Chinese PLA, Beijing 100853, China; Department of Critical Care Medicine, First Medical Center, Chinese PLA General Hospital, Beijing, 100853, China.
| |
Collapse
|
10
|
Yüzen D, Graf I, Diemert A, Arck PC. Climate change and pregnancy complications: From hormones to the immune response. Front Endocrinol (Lausanne) 2023; 14:1149284. [PMID: 37091849 PMCID: PMC10113645 DOI: 10.3389/fendo.2023.1149284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2023] [Accepted: 03/21/2023] [Indexed: 04/08/2023] Open
Abstract
Pregnant women are highly vulnerable to adverse environments. Accumulating evidence highlights that increasing temperatures associated with the ongoing climate change pose a threat to successful reproduction. Heat stress caused by an increased ambient temperature can result in adverse pregnancy outcomes, e.g., preterm birth, stillbirth and low fetal weight. The pathomechanisms through which heat stress interferes with pregnancy maintenance still remain vague, but emerging evidence underscores that the endocrine system is severely affected. It is well known that the endocrine system pivotally contributes to the physiological progression of pregnancy. We review – sometimes speculate - how heat stress can offset hormonal dysregulations and subsequently derail other systems which interact with hormones, such as the immune response. This may account for the heat-stress related threat to successful pregnancy progression, fetal development and long-term children’s health.
Collapse
Affiliation(s)
- Dennis Yüzen
- Laboratory for Experimental Feto-Maternal Medicine, Department of Obstetrics and Prenatal Medicine, University Medical Center of Hamburg-Eppendorf, Hamburg, Germany
- Institute of Immunology, University Medical Center of Hamburg-Eppendorf, Hamburg, Germany
| | - Isabel Graf
- Laboratory for Experimental Feto-Maternal Medicine, Department of Obstetrics and Prenatal Medicine, University Medical Center of Hamburg-Eppendorf, Hamburg, Germany
| | - Anke Diemert
- Laboratory for Experimental Feto-Maternal Medicine, Department of Obstetrics and Prenatal Medicine, University Medical Center of Hamburg-Eppendorf, Hamburg, Germany
| | - Petra Clara Arck
- Laboratory for Experimental Feto-Maternal Medicine, Department of Obstetrics and Prenatal Medicine, University Medical Center of Hamburg-Eppendorf, Hamburg, Germany
| |
Collapse
|
11
|
Ravanelli N, Barry H, Bain AR, Vachon L, Martel C, Gagnon D. Impact of passive heat stress and passive heat acclimation on circulating extracellular vesicles: An exploratory analysis. Exp Physiol 2023; 108:344-352. [PMID: 36621798 PMCID: PMC10103847 DOI: 10.1113/ep090823] [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: 09/17/2022] [Accepted: 12/13/2022] [Indexed: 01/10/2023]
Abstract
NEW FINDINGS What is the central question of this study? How does passive heat stress and subsequent heat acclimation affect the circulating concentration of extracellular vesicles? What is the main finding and its importance? Passive heat stress increased the circulating concentration of total and platelet extracellular vesicles. Seven days of hot water immersion did not modify the change in circulating concentrations of extracellular vesicles during passive heat stress. ABSTRACT This retrospective exploratory analysis aimed to improve our understanding of the effect of passive heat stress and subsequent heat acclimation on the circulating concentration of extracellular vesicles (EVs). Healthy young adults (four females and six males, 25 ± 4 years of age, 1.72 ± 0.08 m in height and weighing 71.6 ± 9.0 kg) were heated with a water-perfused suit before and after seven consecutive days of hot water immersion. Pre-acclimation, participants were heated until oesophageal temperature increased to ∼1.4°C above baseline values. Post-acclimation, participants were heated until oesophageal temperature reached the same absolute value as the pre-acclimation visit (∼38.2°C). Venous blood samples were obtained before and at the end of passive heating to quantify plasma concentrations of EVs from all cell types (CSFE+ ), all cell types except erythrocytes (CSFE+ MHCI+ ), platelets (CSFE+ MHCI+ CD41+ ), endothelial cells (CSFE+ MHCI+ CD62e+ ), red blood cells (CSFE+ CD235a+ ) and leucocytes (CSFE+ MHCI+ CD45+ ) via flow cytometry. Passive heat stress increased the concentration of CFSE+ EVs (46,150,000/ml [3,620,784, 88,679,216], P = 0.036), CFSE+ MHCI+ EVs (28,787,500/ml [9,851,127, 47,723,873], P = 0.021) and CSFE+ MHCI+ CD41+ EVs (28,343,500/ml [9,637,432, 47,049,568], P = 0.008). The concentration of CSFE+ MHCI+ CD62e+ EVs (94,230/ml [-55,099, 243,559], P = 0.187), CSFE+ CD235a+ EVs (-1,414/ml [-15,709, 12,882], P = 0.403) or CSFE+ MHCI+ CD45+ EVs (-192,915/ml [-690,166, 304,336], P = 0.828) did not differ during heat stress. The change in circulating EVs during passive heat stress did not differ after heat acclimation (thermal state × acclimation interactions, all P ≥ 0.180). These results demonstrate that passive heat stress increases the circulating concentration of total and platelet EVs and that passive heat acclimation does not alter this increase.
Collapse
Affiliation(s)
| | - Hadiatou Barry
- Montreal Heart InstituteMontrealQuebecCanada
- Department of Pharmacology and PhysiologyUniversité de MontréalMontrealQuebecCanada
| | - Anthony R. Bain
- Department of KinesiologyUniversity of WindsorWindsorOntarioCanada
| | - Laurent Vachon
- Montreal Heart InstituteMontrealQuebecCanada
- Department of MedicineUniversité de MontréalMontrealQuebecCanada
| | - Catherine Martel
- Montreal Heart InstituteMontrealQuebecCanada
- Department of MedicineUniversité de MontréalMontrealQuebecCanada
| | - Daniel Gagnon
- Montreal Heart InstituteMontrealQuebecCanada
- Department of Pharmacology and PhysiologyUniversité de MontréalMontrealQuebecCanada
- School of Kinesiology and Exercise ScienceUniversité de MontréalMontrealQuebecCanada
| |
Collapse
|
12
|
Horowitz M, Hasin Y. Vascular compliance and left ventricular compliance cross talk: Implications for using long-term heat acclimation in cardiac care. Front Physiol 2023; 14:1074391. [PMID: 36960151 PMCID: PMC10027724 DOI: 10.3389/fphys.2023.1074391] [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: 10/19/2022] [Accepted: 02/23/2023] [Indexed: 03/09/2023] Open
Abstract
1) The first evidence of the beneficial impact of Long-Term-Heat-Acclimation (LTHA) on cardio-vascular compliance was the positive inotropic response and improved left ventricular (LV) compliance noted when isolated hearts from LTHA rats were studied. Human echo study demonstrates that passive HA affects the right ventricle and the atria as well. 2) There is a cross-talk between vascular and cardiac compliance. Vascular compliance per se is defined by central venous pressure-Blood volume relationship-Global Vascular Compliance (GVC). It is determined by the sum of the vascular compliance of the vessels in every organ in any physiological state, varies with LTHA and thus influences cardiac performance. LTHA improves endothelial function, increases NO (nitric oxide) production, in-turn stimulating alterations in ECM (extracellular matrix) via the TGF β1-SMAD pathway. 3) LTHA is associated with transformation from fast to slow myosin, heat acclimation ischemic/hypoxic cross-tolerance and alterations in the extracellular matrix. 4) A human translational study demonstrated improved LV compliance following bypass surgery in LTHA subjects compared to controls. 5) Diastolic dysfunction and the impact of comorbidities with vascular and non- vascular origins are major contributors to the syndrome of heart failure with preserved ejection function (HFPEF). Unfortunately, there is a paucity of treatment modalities that improve diastolic dysfunction. 6) In the current mini-review we suggest that LTHA may be beneficial to HFPEF patients by remodeling cardiac compliance and vascular response.
Collapse
Affiliation(s)
- Michal Horowitz
- Laboratory of Environmental Physiology, Faculty of Dentistry, The Hebrew University of Jerusalem, Jerusalem, Israel
- *Correspondence: Michal Horowitz,
| | | |
Collapse
|
13
|
Murray KO, Clanton TL, Horowitz M. Epigenetic responses to heat: From adaptation to maladaptation. Exp Physiol 2022; 107:1144-1158. [PMID: 35413138 PMCID: PMC9529784 DOI: 10.1113/ep090143] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Accepted: 03/25/2022] [Indexed: 11/08/2022]
Abstract
NEW FINDINGS What is the topic of this review? This review outlines the history of research on epigenetic adaptations to heat exposure. The perspective taken is that adaptations reflect properties of hormesis, whereby low, repeated doses of heat induce adaptation (acclimation/acclimatization); whereas brief, life-threatening exposures can induce maladaptive responses. What advances does it highlight? The epigenetic mechanisms underlying acclimation/acclimatization comprise specific molecular programmes on histones that regulate heat shock proteins transcriptionally and protect the organism from subsequent heat exposures, even after long delays. The epigenetic signalling underlying maladaptive responses might rely, in part, on extensive changes in DNA methylation that are sustained over time and might contribute to later health challenges. ABSTRACT Epigenetics plays a strong role in molecular adaptations to heat by producing a molecular memory of past environmental exposures. Moderate heat, over long periods of time, induces an 'adaptive' epigenetic memory, resulting in a condition of 'resilience' to future heat exposures or cross-tolerance to other forms of toxic stress. In contrast, intense, life-threatening heat exposures, such as severe heat stroke, can result in a 'maladaptive' epigenetic memory that can place an organism at risk of later health complications. These cellular memories are coded by post-translational modifications of histones on the nucleosomes and/or by changes in DNA methylation. They operate by inducing changes in the level of gene transcription and therefore phenotype. The adaptive response to heat acclimation functions, in part, by facilitating transcription of essential heat shock proteins and exhibits a biphasic short programme (maintaining DNA integrity, followed by a long-term consolidation). The latter accelerates acclimation responses after de-acclimation. Although less studied, the maladaptive responses to heat stroke appear to be coded in long-lasting changes in DNA methylation near the promoter region of genes involved with basic cell function. Whether these memories are also encoded in histone modifications is not yet known. There is considerable evidence that both adaptive and maladaptive epigenetic responses to heat can be inherited, although most evidence comes from lower organisms. Future challenges include understanding the signalling mechanisms responsible and discovering new ways to promote adaptive responses while suppressing maladaptive responses to heat, as all life forms adapt to life on a warming planet.
Collapse
Affiliation(s)
- Kevin O. Murray
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO, USA
| | - Thomas L. Clanton
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA
| | - Michal Horowitz
- Laboratory of Environmental Physiology, Faculty of Dentistry, The Hebrew University of Jerusalem, Jerusalem, Israel
| |
Collapse
|
14
|
Périard JD, DeGroot D, Jay O. Exertional heat stroke in sport and the military: epidemiology and mitigation. Exp Physiol 2022; 107:1111-1121. [PMID: 36039024 PMCID: PMC9826288 DOI: 10.1113/ep090686] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 08/12/2022] [Indexed: 01/11/2023]
Abstract
NEW FINDINGS What is the topic of this review? Exertional heat stroke epidemiology in sport and military settings, along with common risk factors and strategies and policies designed to mitigate its occurrence. What advances does it highlight? Individual susceptibility to exertional heat stroke risk is dependent on the interaction of intrinsic and extrinsic factors. Heat policies in sport should assess environmental conditions, as well as the characteristics of the athlete, clothing/equipment worn and activity level of the sport. Exertional heat stroke risk reduction in the military should account for factors specific to training and personnel. ABSTRACT Exertional heat illness occurs along a continuum, developing from the relatively mild condition of muscle cramps, to heat exhaustion, and in some cases to the life-threatening condition of heat stroke. The development of exertional heat stroke (EHS) is associated with an increase in core temperature stemming from inadequate heat dissipation to offset the rate of metabolically generated heat. Susceptibility to EHS is linked to the interaction of several factors including environmental conditions, individual characteristics, health conditions, medication and drug use, behavioural responses, and sport/organisational requirements. Two settings in which EHS is commonly observed are competitive sport and the military. In sport, the exact prevalence of EHS is unclear due to inconsistent exertional heat illness terminology, diagnostic criteria and data reporting. In contrast, exertional heat illness surveillance in the military is facilitated by standardised case definitions, a requirement to report all heat illness cases and a centralised medical record repository. To mitigate EHS risk, several strategies can be implemented by athletes and military personnel, including heat acclimation, ensuring adequate hydration, cold-water immersion and mandated work-to-rest ratios. Organisations may also consider developing sport or military task-specific heat stress policies that account for the evaporative heat loss requirement of participants, relative to the evaporative capacity of the environment. This review examines the epidemiology of EHS along with the strategies and policies designed to reduce its occurrence in sport and military settings. We highlight the nuances of identifying individuals at risk of EHS and summarise the benefits and shortcomings of various mitigation strategies.
Collapse
Affiliation(s)
- Julien D. Périard
- Research Institute for Sport and ExerciseUniversity of CanberraCanberraAustralia
| | - David DeGroot
- Army Heat CenterMartin Army Community HospitalFort BenningGAUSA
| | - Ollie Jay
- Thermal Ergonomics LaboratoryHeat and Health Research IncubatorFaculty of Medicine and HealthUniversity of SydneyCamperdownAustralia
| |
Collapse
|
15
|
Natur S, Damri O, Agam G. The Effect of Global Warming on Complex Disorders (Mental Disorders, Primary Hypertension, and Type 2 Diabetes). INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19159398. [PMID: 35954764 PMCID: PMC9368177 DOI: 10.3390/ijerph19159398] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 07/21/2022] [Accepted: 07/26/2022] [Indexed: 01/09/2023]
Abstract
Multiple studies imply a strong relationship between global warming (GW) and complex disorders. This review summarizes such reports concentrating on three disorders-mental disorders (MD), primary hypertension, and type 2 diabetes (T2D). We also attempt to point at potential mechanisms mediating the effect of GW on these disorders. Concerning mental disorders, immediate candidates are brain levels of heat-shock proteins (HSPs). In addition, given that heat stress increases reactive oxygen species (ROS) levels which may lead to blood-brain barrier (BBB) breakdown and, hence, enhanced protein extravasation in the brain, this might finally cause, or exacerbate mental health. As for hypertension, since its causes are incompletely understood, the mechanism(s) by which heat exposure affects blood pressure (BP) is an open question. Since the kidneys participate in regulating blood volume and BP they are considered as a site of heat-associated disease, hence, we discuss hyperosmolarity as a potential mediator. In addition, we relate to autoimmunity, inflammation, sodium excretion, and HSP70 as risk factors that might play a role in the effect of heat on hypertension. In the case of T2D, we raise two potential mediators of the effect of exposure to ambient hot environment on the disease's incidence-brown adipose tissue metabolism and HSPs.
Collapse
|
16
|
Haron A, Shinder D, Lokshtanov D, Ruzal M, Druyan S. Effects of hypoxic conditions during the plateau period on pre- and posthatch broiler performance. Poult Sci 2022; 101:101597. [PMID: 34936961 PMCID: PMC8703078 DOI: 10.1016/j.psj.2021.101597] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 10/31/2021] [Accepted: 11/02/2021] [Indexed: 11/17/2022] Open
Abstract
Adequate ambient temperature and oxygenation are necessary to maintain normal embryonic development of broilers; however, hypoxia challenge during incubation can aid in improving regulatory plasticity and lead to different phenotypes later in life. This study aimed to examine the effects of moderate hypoxia (O2 17%) during the plateau phase on the embryonic physiological parameters and on posthatch performance (growth rate, feed consumption and feed conversion) up to the age of poultry marketing. The study included examined embryos exposed to O2 17% for 12 h per day (h/d) from E16 through E18 (designated as 12H), or O2 17% continuously, from E16 through E17 (designated as 48H) and a standard incubation control group (21% O2). Physiological and morphological parameters of embryos and hatched chicks were measured. Male Chicks from all 3 treatment groups were raised under recommended temperature regime, and body weight, feed intake and FCR were recorded on a weekly basis. The intermittent hypoxia protocol (12H), allowed embryos to properly adapt to the shortage of oxygen, compensate for the gap in body mass that developed following the first exposure window, and hatch with characteristics similar to those of the control embryos. In contrast, while the 48H embryos were able to adapt to the hypoxic stress, the prolonged exposure prevented them from catching up with both control and 12H embryos. Broilers that were subjected to hypoxia showed hatchling body weights and growth rates similar to those of controls, throughout the entire growth phase. During the fifth wk, lower feed consumption was observed in the 12H and 48H groups and became significantly lower than the control chicks in the sixth wk of growth. Following hypoxia exposure, chicks managed to reach normal body weight with less feed, with the 12H group demonstrating lower and more efficient FCR during the last 2 wk of growth. Broiler embryos reacted to plateau-phase hypoxia challenge with numerous physiological and metabolic modifications. The prudent alterations in metabolism and cardiovascular system during exposure to hypoxia and posthatch, resulted in more efficient energy utilization in broilers, which may have a long-lasting enhancing effect on posthatching thermotolerance and sustainability in chicks reared under sub-optimal environmental conditions.
Collapse
Affiliation(s)
- A Haron
- Institute of Animal Science, Agricultural Research Organization, Volcani Center, Bet Dagan 7528809, Israel; The Robert H. Smith Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem, Rehovot, Israel
| | - D Shinder
- Institute of Animal Science, Agricultural Research Organization, Volcani Center, Bet Dagan 7528809, Israel
| | - D Lokshtanov
- Institute of Animal Science, Agricultural Research Organization, Volcani Center, Bet Dagan 7528809, Israel
| | - M Ruzal
- Institute of Animal Science, Agricultural Research Organization, Volcani Center, Bet Dagan 7528809, Israel
| | - S Druyan
- Institute of Animal Science, Agricultural Research Organization, Volcani Center, Bet Dagan 7528809, Israel.
| |
Collapse
|
17
|
García-Martínez S, Latorre R, Sánchez-Hurtado MA, Sánchez-Margallo FM, Bernabò N, Romar R, López-Albors O, Coy P. Mimicking the temperature gradient between the sow's oviduct and uterus improves in vitro embryo culture output. Mol Hum Reprod 2021; 26:748-759. [PMID: 32647896 DOI: 10.1093/molehr/gaaa053] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 06/11/2020] [Indexed: 12/21/2022] Open
Abstract
This work was designed to determine temperature conditions within the reproductive tract of the female pig and study their impact on ARTs. Temperatures were recorded using a laparo-endoscopic single-site surgery assisted approach and a miniaturized probe. Sows and gilts were used to address natural cycle and ovarian stimulation treatments, respectively. According to in vivo values, IVF was performed at three temperature conditions (37.0°C, 38.5°C and 39.5°C) and presumptive zygotes were cultured in these conditions for 20 h, while further embryo culture (EC) (21-168 h post-insemination) was maintained at 38.5°C. After 20 h, different fertility parameters were assessed. During EC, cleavage and blastocyst stages were evaluated. Sperm membrane fluidity at the experimental temperatures was studied by using differential scanning calorimetry and fluorescence recovery after photobleaching techniques. An increasing temperature gradient of 1.5°C was found between the oviduct and uterus of sows (P < 0.05) and when this gradient was transferred to pig in vitro culture, the number of poly-nuclear zygotes after IVF was reduced and the percentage of blastocysts was increased. Moreover, the temperature transition phase for the boar sperm membrane (37.0°C) coincided with the temperature registered in the sow oviduct, and sperm membranes were more fluid at 37.0°C compared with those of sperm incubated at higher temperatures (38.5°C and 39.5°C). These data suggest that there may be an impact of physiological temperature gradients on human embryo development.
Collapse
Affiliation(s)
- S García-Martínez
- Department of Physiology, Facultad de Veterinaria, Campus Internacional de Excelencia de Educación Superior (Campus Mare Nostrum). Universidad de Murcia, Murcia, Spain.,Instituto Murciano de Investigación Biosanitaria Virgen de la Arrixaca (IMIB-Arrixaca), Murcia, Spain
| | - R Latorre
- Department of Anatomy & Comparative Pathology, Facultad de Veterinaria, Campus Internacional de Excelencia de Educación Superior (Campus Mare Nostrum), Universidad de Murcia, Murcia, Spain
| | - M A Sánchez-Hurtado
- Laparoscopy Unit, Minimally Invasive Surgery Center Jesús Usón, Cáceres, Spain
| | | | - N Bernabò
- Department of Comparative Biomedical Sciences, Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, Teramo, Italy
| | - R Romar
- Department of Physiology, Facultad de Veterinaria, Campus Internacional de Excelencia de Educación Superior (Campus Mare Nostrum). Universidad de Murcia, Murcia, Spain.,Instituto Murciano de Investigación Biosanitaria Virgen de la Arrixaca (IMIB-Arrixaca), Murcia, Spain
| | - O López-Albors
- Department of Anatomy & Comparative Pathology, Facultad de Veterinaria, Campus Internacional de Excelencia de Educación Superior (Campus Mare Nostrum), Universidad de Murcia, Murcia, Spain
| | - P Coy
- Department of Physiology, Facultad de Veterinaria, Campus Internacional de Excelencia de Educación Superior (Campus Mare Nostrum). Universidad de Murcia, Murcia, Spain.,Instituto Murciano de Investigación Biosanitaria Virgen de la Arrixaca (IMIB-Arrixaca), Murcia, Spain
| |
Collapse
|
18
|
Périard JD, Eijsvogels TMH, Daanen HAM. Exercise under heat stress: thermoregulation, hydration, performance implications, and mitigation strategies. Physiol Rev 2021; 101:1873-1979. [PMID: 33829868 DOI: 10.1152/physrev.00038.2020] [Citation(s) in RCA: 155] [Impact Index Per Article: 51.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
A rise in body core temperature and loss of body water via sweating are natural consequences of prolonged exercise in the heat. This review provides a comprehensive and integrative overview of how the human body responds to exercise under heat stress and the countermeasures that can be adopted to enhance aerobic performance under such environmental conditions. The fundamental concepts and physiological processes associated with thermoregulation and fluid balance are initially described, followed by a summary of methods to determine thermal strain and hydration status. An outline is provided on how exercise-heat stress disrupts these homeostatic processes, leading to hyperthermia, hypohydration, sodium disturbances, and in some cases exertional heat illness. The impact of heat stress on human performance is also examined, including the underlying physiological mechanisms that mediate the impairment of exercise performance. Similarly, the influence of hydration status on performance in the heat and how systemic and peripheral hemodynamic adjustments contribute to fatigue development is elucidated. This review also discusses strategies to mitigate the effects of hyperthermia and hypohydration on exercise performance in the heat by examining the benefits of heat acclimation, cooling strategies, and hyperhydration. Finally, contemporary controversies are summarized and future research directions are provided.
Collapse
Affiliation(s)
- Julien D Périard
- University of Canberra Research Institute for Sport and Exercise, Bruce, Australia
| | - Thijs M H Eijsvogels
- Department of Physiology, Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Hein A M Daanen
- Department of Human Movement Sciences, Faculty of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| |
Collapse
|
19
|
Brunt VE, Minson CT. Heat therapy: mechanistic underpinnings and applications to cardiovascular health. J Appl Physiol (1985) 2021; 130:1684-1704. [PMID: 33792402 DOI: 10.1152/japplphysiol.00141.2020] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Cardiovascular diseases (CVD) are the leading cause of death worldwide, and novel therapies are drastically needed to prevent or delay the onset of CVD to reduce the societal and healthcare burdens associated with these chronic diseases. One such therapy is "heat therapy," or chronic, repeated use of hot baths or saunas. Although using heat exposure to improve health is not a new concept, it has received renewed attention in recent years as a growing number of studies have demonstrated robust and widespread beneficial effects of heat therapy on cardiovascular health. Here, we review the existing literature, with particular focus on the molecular mechanisms that underscore the cardiovascular benefits of this practice.
Collapse
Affiliation(s)
- Vienna E Brunt
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, Colorado.,Department of Human Physiology, University of Oregon, Eugene, Oregon
| | | |
Collapse
|
20
|
Cao Y, Liu Y, Dong Q, Wang T, Niu C. Alterations in the gut microbiome and metabolic profile in rats acclimated to high environmental temperature. Microb Biotechnol 2021; 15:276-288. [PMID: 33620148 PMCID: PMC8719808 DOI: 10.1111/1751-7915.13772] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Revised: 01/26/2021] [Accepted: 01/30/2021] [Indexed: 12/29/2022] Open
Abstract
Heat acclimation (HA) is the best strategy to improve heat stress tolerance by inducing positive physiological adaptations. Evidence indicates that the gut microbiome plays a fundamental role in the development of HA, and modulation of gut microbiota can improve tolerance to heat exposure and decrease the risks of heat illness. In this study, for the first time, we applied 16S rRNA gene sequencing and untargeted liquid chromatography–mass spectrometry (LC‐MS) metabolomics to explore variations in the gut microbiome and faecal metabolic profiles in rats after HA. The gut microbiota of HA subjects exhibited higher diversity and richer microbes. HA altered the gut microbiota composition with significant increases in the genera Lactobacillus (a major probiotic) and Oscillospira alongside significant decreases in the genera Blautia and Allobaculum. The faecal metabolome was also significantly changed after HA, and among the 13 perturbed metabolites, (S)‐AL 8810 and celastrol were increased. Moreover, the two increased genera were positively correlated with the two upregulated metabolites and negatively correlated with the other 11 downregulated metabolites, while the correlations between the two decreased genera and the upregulated/downregulated metabolites were completely contrary. In summary, both the structure of the gut microbiome community and the faecal metabolome were improved after 28 days of HA. These findings provide novel insights regarding the improvement of the gut microbiome and its functions as a potential mechanism by which HA confers protection against heat stress.
Collapse
Affiliation(s)
- Yang Cao
- Department of Environmental Medicine, Tianjin Institute of Environmental and Operational Medicine, Tianjin, 300050, China
| | - Ying Liu
- Department of Environmental Medicine, Tianjin Institute of Environmental and Operational Medicine, Tianjin, 300050, China
| | - Qingyang Dong
- Department of Environmental Medicine, Tianjin Institute of Environmental and Operational Medicine, Tianjin, 300050, China
| | - Tao Wang
- Department of Environmental Medicine, Tianjin Institute of Environmental and Operational Medicine, Tianjin, 300050, China
| | - Chao Niu
- Department of Environmental Medicine, Tianjin Institute of Environmental and Operational Medicine, Tianjin, 300050, China
| |
Collapse
|
21
|
Four-month operational heat acclimatization positively affects the level of heat tolerance 6 months later. Sci Rep 2020; 10:20260. [PMID: 33219295 PMCID: PMC7680124 DOI: 10.1038/s41598-020-77358-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 10/30/2020] [Indexed: 12/02/2022] Open
Abstract
Benefits obtained after heat acclimation/acclimatization should be completely lost after an estimated period of 6 weeks. However, this estimate is still hypothetical. We evaluate the long-term effects of heat acclimatization on the level of heat tolerance. Physiological and subjective markers of heat tolerance were assessed during a heat stress test (HST: 3 × 8-min runs outdoors [~ 40 °C and 20% RH] at 50% of their estimated speed at VO2max) performed on the 2nd day upon arrival to the desert military base in the United Arab Emirates after a first day of mostly passive exposure to heat. Among the 50 male French soldiers, 25 partook in a 4-month military mission in countries characterized by a hot environment ~ 6 months prior to the study (HA). The other 25 participants were never heat acclimatized (CT). Rectal temperature (p = 0.023), heart rate (p = 0.033), and perceived exertion (p = 0.043) were lower in the HA than CT group at the end of HST. Soldiers who experienced a former 4-month period of natural heat acclimatization very likely had a higher level of heat tolerance during exercise in the heat, even 6 months after returning from the previous desert mission, than that of their non-acclimatized counterparts.
Collapse
|
22
|
Amano T, Fujii N, Kenny GP, Okamoto Y, Inoue Y, Kondo N. Effects of L-type voltage-gated Ca 2+ channel blockade on cholinergic and thermal sweating in habitually trained and untrained men. Am J Physiol Regul Integr Comp Physiol 2020; 319:R584-R591. [PMID: 32966123 DOI: 10.1152/ajpregu.00167.2020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
We evaluated the hypothesis that the activation of L-type voltage-gated Ca2+ channels contributes to exercise training-induced augmentation in cholinergic sweating. On separate days, 10 habitually trained and 10 untrained men participated in two experimental protocols. Prior to each protocol, we administered 1% verapamil (Verapamil, L-type voltage-gated Ca2+ channel blocker) and saline (Control) at forearm skin sites on both arms via transdermal iontophoresis. In protocol 1, we administered low (0.001%) and high (1%) doses of pilocarpine at both the verapamil-treated and verapamil-untreated forearm sites. In protocol 2, participants were passively heated by immersing their limbs in hot water (43°C) until rectal temperature increased by 1.0°C above baseline resting levels. Sweat rate at all forearm sites was continuously measured throughout both protocols. Pilocarpine-induced sweating in Control was higher in trained than in untrained men for both the concentrations of pilocarpine (both P ≤ 0.001). Pilocarpine-induced sweating at the low-dose site was attenuated at the Verapamil versus the Control site in both the groups (both P ≤ 0.004), albeit the reduction was greater in trained as compared with in untrained men (P = 0.005). The verapamil-mediated reduction in sweating remained intact at the high-dose pilocarpine site in the untrained men (P = 0.004) but not the trained men (P = 0.180). Sweating did not differ between Control and Verapamil sites with increases in rectal temperature in both groups (interaction, P = 0.571). We show that activation of L-type voltage-gated Ca2+ channels modulates sweat production in habitually trained men induced by a low dose of pilocarpine. However, no effect on sweating was observed during passive heating in either group.
Collapse
Affiliation(s)
- Tatsuro Amano
- Laboratory for Exercise and Environmental Physiology, Faculty of Education, Niigata University, Niigata, Japan
| | - Naoto Fujii
- Faculty of Health and Sport Sciences, University of Tsukuba, Tsukuba City, Japan
| | - Glen P Kenny
- Human and Environmental Physiology Research Unit, University of Ottawa, Ottawa, Canada
| | - Yumi Okamoto
- Laboratory for Exercise and Environmental Physiology, Faculty of Education, Niigata University, Niigata, Japan
| | - Yoshimitsu Inoue
- Laboratory for Human Performance Research, Osaka International University, Osaka, Japan
| | - Narihiko Kondo
- Laboratory for Applied Human Physiology, Graduate School of Human Development and Environment, Kobe University, Kobe, Japan
| |
Collapse
|
23
|
Collins J, Maughan RJ, Gleeson M, Bilsborough J, Jeukendrup A, Morton JP, Phillips SM, Armstrong L, Burke LM, Close GL, Duffield R, Larson-Meyer E, Louis J, Medina D, Meyer F, Rollo I, Sundgot-Borgen J, Wall BT, Boullosa B, Dupont G, Lizarraga A, Res P, Bizzini M, Castagna C, Cowie CM, D'Hooghe M, Geyer H, Meyer T, Papadimitriou N, Vouillamoz M, McCall A. UEFA expert group statement on nutrition in elite football. Current evidence to inform practical recommendations and guide future research. Br J Sports Med 2020; 55:416. [PMID: 33097528 DOI: 10.1136/bjsports-2019-101961] [Citation(s) in RCA: 107] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/18/2020] [Indexed: 01/09/2023]
Abstract
Football is a global game which is constantly evolving, showing substantial increases in physical and technical demands. Nutrition plays a valuable integrated role in optimising performance of elite players during training and match-play, and maintaining their overall health throughout the season. An evidence-based approach to nutrition emphasising, a 'food first' philosophy (ie, food over supplements), is fundamental to ensure effective player support. This requires relevant scientific evidence to be applied according to the constraints of what is practical and feasible in the football setting. The science underpinning sports nutrition is evolving fast, and practitioners must be alert to new developments. In response to these developments, the Union of European Football Associations (UEFA) has gathered experts in applied sports nutrition research as well as practitioners working with elite football clubs and national associations/federations to issue an expert statement on a range of topics relevant to elite football nutrition: (1) match day nutrition, (2) training day nutrition, (3) body composition, (4) stressful environments and travel, (5) cultural diversity and dietary considerations, (6) dietary supplements, (7) rehabilitation, (8) referees and (9) junior high-level players. The expert group provide a narrative synthesis of the scientific background relating to these topics based on their knowledge and experience of the scientific research literature, as well as practical experience of applying knowledge within an elite sports setting. Our intention is to provide readers with content to help drive their own practical recommendations. In addition, to provide guidance to applied researchers where to focus future efforts.
Collapse
Affiliation(s)
- James Collins
- Intra Performance Group, London, UK.,Performance and Research Team, Arsenal Football Club, London, UK
| | | | - Michael Gleeson
- School of Sports Exercise and Health Sciences, Loughborough University, Loughborough, UK
| | - Johann Bilsborough
- Faculty of Health, University of Technology, Sydney, New South Wales, Australia.,New England Patriots, Foxboro, MA, USA
| | - Asker Jeukendrup
- School of Sports Exercise and Health Sciences, Loughborough University, Loughborough, UK.,MySport Science, Birmingham, UK
| | - James P Morton
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK
| | - S M Phillips
- Kinesiology, McMaster University, Hamilton, Ontario, Canada
| | - Lawrence Armstrong
- Human Performance Laboratory, University of Connecticut, Storrs, CT, USA
| | - Louise M Burke
- Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC, Australia
| | - Graeme L Close
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK
| | - Rob Duffield
- Faculty of Health, University of Technology, Sydney, New South Wales, Australia.,Medical Department, Football Federation Australia, Sydney, New South Wales, Australia
| | - Enette Larson-Meyer
- Department of Human Nutrition, Foods, and Exercise, Virginia Tech, Blacksburg, VA, USA
| | - Julien Louis
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK
| | - Daniel Medina
- Athlete Care and Performance, Monumental Sports & Entertainment, Washington, DC, USA
| | - Flavia Meyer
- Federal University of Rio Grande do Sul, Porto Alegre, Brazil
| | - Ian Rollo
- School of Sports Exercise and Health Sciences, Loughborough University, Loughborough, UK.,PepsiCo Life Sciences, Global R&D, Gatorade Sports Science Institute, Birmingham, UK
| | | | - Benjamin T Wall
- Department of Sport and Health Sciences, College of Life and Environmental Sciences, University of Exeter, Exeter, UK
| | | | - Gregory Dupont
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK
| | | | - Peter Res
- Dutch Olympic Team, Amsterdam, Netherlands
| | - Mario Bizzini
- Research and Human Performance Lab, Schulthess Clinic, Zurich, Switzerland
| | - Carlo Castagna
- University of Rome Tor Vergata, Rome, Italy.,Technical Department, Italian Football Federation (FIGC), Florence, Italy.,Italian Football Referees Association, Bologna, Italy
| | - Charlotte M Cowie
- Technical Directorate, Football Association, Burton upon Trent, UK.,Medical Committee, UEFA, Nyon, Switzerland
| | - Michel D'Hooghe
- Medical Committee, UEFA, Nyon, Switzerland.,Medical Centre of Excelence, Schulthess Clinic, Zurich, Switzerland
| | - Hans Geyer
- Center for Preventive Doping Research, German Sport University Cologne, Cologne, Germany
| | - Tim Meyer
- Medical Committee, UEFA, Nyon, Switzerland.,Institute of Sports and Preventive Medicine, Saarland University, Saarbrücken, Germany
| | | | | | - Alan McCall
- Performance and Research Team, Arsenal Football Club, London, UK .,Medical Department, Football Federation Australia, Sydney, New South Wales, Australia.,Sport, Exercise and Health Sciences, School of Applied Sciences, Edinburgh Napier University, Edinburgh, UK
| |
Collapse
|
24
|
Amano T, Fujii N, Kenny GP, Nishiyasu T, Inoue Y, Kondo N. The relative contribution of α- and β-adrenergic sweating during heat exposure and the influence of sex and training status. Exp Dermatol 2020; 29:1216-1224. [PMID: 33015872 DOI: 10.1111/exd.14208] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 09/14/2020] [Accepted: 09/27/2020] [Indexed: 02/04/2023]
Abstract
While human eccrine sweat glands respond to adrenergic agonists, there remains a paucity of information on the factors modulating this response. Thus, we assessed the relative contribution of α- and β-adrenergic sweating during a heat exposure and as a function of individual factors of sex and training status. α- and β-adrenergic sweating was assessed in forty-eight healthy young men (n = 35) and women (n = 13) including endurance-trained (n = 12) and untrained men (n = 12) under non-heat exposure (temperate, 25°C; n = 17) and heat exposure (hot, 35°C; n = 48) conditions using transdermal iontophoresis of phenylephrine (α-adrenergic agonist) and salbutamol (β-adrenergic agonist) on the ventral forearm, respectively. Adrenergic sweating was also measured after iontophoretic administration of atropine (muscarinic receptor antagonist) or saline (control) to evaluate how changes in muscarinic receptor activity modulate the adrenergic response to a heat exposure (n = 12). α- and β-adrenergic sweating was augmented in hot compared with temperate conditions (both P ≤ .014), albeit the relative increase was greater in β (~5.4-fold)- as compared to α (~1.5-fold)-adrenergic-mediated sweating response. However, both α- and β-adrenergic sweating was abolished by atropinization (P = .001). Endurance-trained men showed an augmentation in α- (P = .043) but not β (P = .960)-adrenergic sweating as compared to untrained men. Finally, a greater α- and β-adrenergic sweating response (both P ≤ .001) was measured in habitually active men than in women. We show that heat exposure augments α-and β-adrenergic sweating differently via mechanisms associated with altered muscarinic receptor activity. Sex and training status modulate this response.
Collapse
Affiliation(s)
- Tatsuro Amano
- Laboratory for Exercise and Environmental Physiology, Faculty of Education, Niigata University, Niigata, Japan
| | - Naoto Fujii
- Faculty of Health and Sport Sciences, University of Tsukuba, Tsukuba City, Japan
| | - Glen P Kenny
- Human and Environmental Physiology Research Unit, University of Ottawa, Ottawa, Canada
| | - Takeshi Nishiyasu
- Faculty of Health and Sport Sciences, University of Tsukuba, Tsukuba City, Japan
| | - Yoshimitsu Inoue
- Laboratory for Human Performance Research, Osaka International University, Osaka, Japan
| | - Narihiko Kondo
- Laboratory for Applied Human Physiology, Graduate School of Human Development and Environment, Kobe University, Kobe, Japan
| |
Collapse
|
25
|
Foster J, Hodder SG, Lloyd AB, Havenith G. Individual Responses to Heat Stress: Implications for Hyperthermia and Physical Work Capacity. Front Physiol 2020; 11:541483. [PMID: 33013476 PMCID: PMC7516259 DOI: 10.3389/fphys.2020.541483] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 08/18/2020] [Indexed: 12/11/2022] Open
Abstract
Background Extreme heat events are increasing in frequency, severity, and duration. It is well known that heat stress can have a negative impact on occupational health and productivity, particularly during physical work. However, there are no up-to-date reviews on how vulnerability to heat changes as a function of individual characteristics in relation to the risk of hyperthermia and work capacity loss. The objective of this narrative review is to examine the role of individual characteristics on the human heat stress response, specifically in relation to hyperthermia risk and productivity loss in hot workplaces. Finally, we aim to generate practical guidance for industrial hygienists considering our findings. Factors included in the analysis were body mass, body surface area to mass ratio, body fat, aerobic fitness and training, heat adaptation, aging, sex, and chronic health conditions. Findings We found the relevance of any factor to be dynamic, based on the work-type (fixed pace or relative to fitness level), work intensity (low, moderate, or heavy work), climate type (humidity, clothing vapor resistance), and variable of interest (risk of hyperthermia or likelihood of productivity loss). Heat adaptation, high aerobic fitness, and having a large body mass are the most protective factors during heat exposure. Primary detrimental factors include low fitness, low body mass, and lack of heat adaptation. Aging beyond 50 years, being female, and diabetes are less impactful negative factors, since their independent effect is quite small in well matched participants. Skin surface area to mass ratio, body composition, hypertension, and cardiovascular disease are not strong independent predictors of the heat stress response. Conclusion Understanding how individual factors impact responses to heat stress is necessary for the prediction of heat wave impacts on occupational health and work capacity. The recommendations provided in this report could be utilized to help curtail hyperthermia risk and productivity losses induced by heat.
Collapse
Affiliation(s)
- Josh Foster
- Environmental Ergonomics Research Centre, Loughborough University, Loughborough, United Kingdom
| | - Simon G Hodder
- Environmental Ergonomics Research Centre, Loughborough University, Loughborough, United Kingdom
| | - Alex B Lloyd
- Environmental Ergonomics Research Centre, Loughborough University, Loughborough, United Kingdom
| | - George Havenith
- Environmental Ergonomics Research Centre, Loughborough University, Loughborough, United Kingdom
| |
Collapse
|
26
|
Wu J, Zhang W, Li C. Recent Advances in Genetic and Epigenetic Modulation of Animal Exposure to High Temperature. Front Genet 2020; 11:653. [PMID: 32733534 PMCID: PMC7358359 DOI: 10.3389/fgene.2020.00653] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 05/29/2020] [Indexed: 12/12/2022] Open
Abstract
Animals have evolved multiple systems, including genetic and epigenetic systems, to respond accordingly to heat exposure and heat acclimation. Heat exposure greatly affects immunity, changes metabolic processes, and poses a serious threat to animals. Heat acclimation is induced by repeated organism exposure to heat stress to dissipate heat. This review focuses on genetic modulation via heat shock transcription factors and calcium as two important factors and compares the changes in HSPs under heat stress and heat acclimation. Epigenetic regulation summarizes the role of HSPs in DNA methylation and histone modifications under heat stress and heat acclimation. These genetic and epigenetic modifications protect cells from thermal damage by mediating the transcriptional levels of heat-responsive genes. This review highlights recent advances in the genetic and epigenetic control of animal thermal responses and their interactions.
Collapse
Affiliation(s)
- Jiong Wu
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Ningbo University, Ningbo, China
| | - Weiwei Zhang
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Ningbo University, Ningbo, China
| | - Chenghua Li
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Ningbo University, Ningbo, China.,Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| |
Collapse
|
27
|
Fleischmann C, Bar-Ilan N, Horowitz M, Bruchim Y, Deuster P, Heled Y. Astaxanthin supplementation impacts the cellular HSP expression profile during passive heating. Cell Stress Chaperones 2020; 25:549-558. [PMID: 31970694 PMCID: PMC7192986 DOI: 10.1007/s12192-019-01061-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 12/09/2019] [Accepted: 12/12/2019] [Indexed: 12/26/2022] Open
Abstract
Astaxanthin is a powerful carotenoid antioxidant prevalent in marine organisms and approved as a food supplement. Recent studies have demonstrated Astaxanthin's beneficial attributes in various health states. Following initial reports of potential heat protective properties in Astaxanthin supplemented rats, we present here results of a novel study examining the effect of Astaxanthin supplementation on the heat shock response in rats in relation to core temperature (Tc) and the ensuing physiological strain. Two hours of heat stress at 41 °C during which rats developed their thermoregulatory hyperthermic plateau resulted in progressive increases in HSP72 and HSP27 in the Astaxanthin (Oleoresin)-treated group but not in the control (Olive oil) group. Enhanced elevation in HSPs suggests that Astaxanthin supplementation may augment the cellular stress protective response to heat stress.
Collapse
Affiliation(s)
- Chen Fleischmann
- The Institute of Military Physiology, IDF Medical Corps, Tel Hashomer, Israel.
- Heller Institute of Medical Research, Sheba Medical Center, Tel Hashomer, Israel.
- Laboratory of Environmental Physiology, The Hebrew University of Jerusalem, Jerusalem, Israel.
| | - Netta Bar-Ilan
- Laboratory of Environmental Physiology, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Michal Horowitz
- Laboratory of Environmental Physiology, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Yaron Bruchim
- Laboratory of Environmental Physiology, The Hebrew University of Jerusalem, Jerusalem, Israel
- Human Performance Resource Center, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - Patricia Deuster
- Emergency and Specialist Veterinary Center, Ben-Shemen Youth Village, Israel
| | - Yuval Heled
- Heller Institute of Medical Research, Sheba Medical Center, Tel Hashomer, Israel
- The Kibbutzim College, Tel Aviv, Israel
| |
Collapse
|
28
|
David SA, Vitorino Carvalho A, Gimonnet C, Brionne A, Hennequet-Antier C, Piégu B, Crochet S, Couroussé N, Bordeau T, Bigot Y, Collin A, Coustham V. Thermal Manipulation During Embryogenesis Impacts H3K4me3 and H3K27me3 Histone Marks in Chicken Hypothalamus. Front Genet 2019; 10:1207. [PMID: 31850067 PMCID: PMC6889634 DOI: 10.3389/fgene.2019.01207] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 11/01/2019] [Indexed: 12/29/2022] Open
Abstract
Changes in gene activity through epigenetic alterations induced by early environmental challenges during embryogenesis are known to impact the phenotype, health, and disease risk of animals. Learning how environmental cues translate into persisting epigenetic memory may open new doors to improve robustness and resilience of developing animals. It has previously been shown that the heat tolerance of male broiler chickens was improved by cyclically elevating egg incubation temperature. The embryonic thermal manipulation enhanced gene expression response in muscle (P. major) when animals were heat challenged at slaughter age, 35 days post-hatch. However, the molecular mechanisms underlying this phenomenon remain unknown. Here, we investigated the genome-wide distribution, in hypothalamus and muscle tissues, of two histone post-translational modifications, H3K4me3 and H3K27me3, known to contribute to environmental memory in eukaryotes. We found 785 H3K4me3 and 148 H3K27me3 differential peaks in the hypothalamus, encompassing genes involved in neurodevelopmental, metabolic, and gene regulation functions. Interestingly, few differences were identified in the muscle tissue for which differential gene expression was previously described. These results demonstrate that the response to embryonic thermal manipulation (TM) in chicken is mediated, at least in part, by epigenetic changes in the hypothalamus that may contribute to the later-life thermal acclimation.
Collapse
Affiliation(s)
| | | | | | | | | | - Benoît Piégu
- PRC, CNRS, IFCE, INRA, Université de Tours, Nouzilly, France
| | | | | | | | - Yves Bigot
- PRC, CNRS, IFCE, INRA, Université de Tours, Nouzilly, France
| | - Anne Collin
- BOA, INRA, Université de Tours, Nouzilly, France
| | | |
Collapse
|
29
|
Levesque KD, Wright PA, Bernier NJ. Cross Talk without Cross Tolerance: Effect of Rearing Temperature on the Hypoxia Response of Embryonic Zebrafish. Physiol Biochem Zool 2019; 92:349-364. [DOI: 10.1086/703178] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
30
|
McConn BR, Koskinen A, Denbow DM, Gilbert ER, Siegel PB, Cline MA. Central injection of oxytocin reduces food intake and affects hypothalamic and adipose tissue gene expression in chickens. Domest Anim Endocrinol 2019; 67:11-20. [PMID: 30660023 DOI: 10.1016/j.domaniend.2018.10.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Revised: 10/15/2018] [Accepted: 10/26/2018] [Indexed: 01/09/2023]
Abstract
Oxytocin (OT) is a well-characterized neurotransmitter that participates in a wide range of physiological processes including the inhibition of food intake. The avian ortholog, mesotocin (MT), differs from OT by a single amino acid. Little is known regarding the function of OT in regulating energy balance in birds; thus, this study was designed to determine the effects of central OT injection on food intake and adipose tissue physiology in chicks. At 4-d post-hatch, broiler chicks were fasted for 3 h and injected intracerebroventricularly with 0 (vehicle), 0.63, 2.5, 5.0, or 10 nmol OT. Oxytocin decreased food and water intake during the entire 180-min observation period. The reduction in water intake was likely not prandial because chicks that were food restricted after OT injection also drank less. There was increased c-Fos immunoreactivity in several appetite-associated hypothalamic nuclei in OT-injected chicks at 1 h, including the arcuate (ARC), dorsomedial nucleus (DMN), lateral hypothalamus (LH), paraventricular nucleus (PVN), and ventromedial hypothalamus (VMH). OT treatment was associated with reduced hypothalamic corticotropin-releasing factor (CRF) mRNA and increased cloacal temperature at 1 h post-injection. We then investigated appetite- and adipose tissue-associated effects of OT in chicks from lines that have undergone long-term selection for either low (LWS) or high (HWS) juvenile body weight. Central injection of OT decreased food intake in both lines with the magnitude of response greater in the HWS than LWS chicks. Adipose tissue abundance of fatty acid-binding protein 4, monoglyceride lipase (MGLL), MT, and perilipin-1 mRNA was greater in LWS than HWS chicks. Lipoprotein lipase, MGLL, and MT mRNAs increased in response to OT injection in LWS but not HWS chicks. In conclusion, central injection of OT induced anorexia, reduced water intake, increased body temperature, and was associated with activation of the ARC, DMN, LH, PVN, and VMH in the hypothalamus. The effects on appetite and body temperature may involve CRF signaling in the hypothalamus and lipolysis in the adipose tissue, respectively. There were differences in the appetite, and adipose tissue response to OT in body weight-selected lines of chicks supports that MT plays a role in energy balance regulation in chickens.
Collapse
Affiliation(s)
- Betty R McConn
- Department of Animal and Poultry Sciences, Virginia Tech, Blacksburg, VA 24061, USA
| | - Anna Koskinen
- Department of Animal and Poultry Sciences, Virginia Tech, Blacksburg, VA 24061, USA
| | - D Michael Denbow
- Department of Animal and Poultry Sciences, Virginia Tech, Blacksburg, VA 24061, USA
| | - Elizabeth R Gilbert
- Department of Animal and Poultry Sciences, Virginia Tech, Blacksburg, VA 24061, USA
| | - Paul B Siegel
- Department of Animal and Poultry Sciences, Virginia Tech, Blacksburg, VA 24061, USA
| | - Mark A Cline
- Department of Animal and Poultry Sciences, Virginia Tech, Blacksburg, VA 24061, USA.
| |
Collapse
|
31
|
|
32
|
Miles C, Mayo B, Beaven CM, McMaster DT, Sims ST, Hébert-Losier K, Driller M. Resistance training in the heat improves strength in professional rugby athletes. SCI MED FOOTBALL 2019. [DOI: 10.1080/24733938.2019.1566764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- Cory Miles
- Health, Sport and Human Performance, University of Waikato, Hamilton, New Zealand
| | - Brad Mayo
- Health, Sport and Human Performance, University of Waikato, Hamilton, New Zealand
- Faculty of Health, Sport and Human Performance, University of Waikato, Mount Maunganui, New Zealand
| | - C. Martyn Beaven
- Health, Sport and Human Performance, University of Waikato, Hamilton, New Zealand
| | - Daniel T. McMaster
- Health, Sport and Human Performance, University of Waikato, Hamilton, New Zealand
| | - Stacy T. Sims
- Health, Sport and Human Performance, University of Waikato, Hamilton, New Zealand
| | - Kim Hébert-Losier
- Health, Sport and Human Performance, University of Waikato, Hamilton, New Zealand
| | - Matthew Driller
- Health, Sport and Human Performance, University of Waikato, Hamilton, New Zealand
| |
Collapse
|
33
|
Park J, Shin S, Lee JY. Effects of alternating exposure to cold and heat for 14 days on cold tolerance in winter. J Therm Biol 2019; 79:1-7. [PMID: 30612669 DOI: 10.1016/j.jtherbio.2018.11.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Revised: 11/13/2018] [Accepted: 11/13/2018] [Indexed: 10/27/2022]
Abstract
People are exposed to heat regularly due to their jobs or daily habits in cold winter, but few studies have reported whether parallel heat and cold exposure and diminish cold acclimation. This study was conducted to investigate the effects of alternating exposure to cold and heat on cold tolerance in eight young males. A daily acclimation program to cold and heat, which consisted of 2-h sitting at 10 °C air in the morning and 2-h running and rest at 30 °C air in the afternoon, was conducted for 14 consecutive days. Eight male subjects participated in a cold tolerance test (10 °C [ ± 0.3], 40%RH[ ± 3]) before (PRE) and after (POST) completing the alternating exposure program. During the cold tolerance test, subjects remained sitting upright on a chair for 60 min. Rectal temperature (Tre) was lower in POST than in PRE during the 60-min cold tolerance test (P = 0.027). During the cold tolerance test, systolic, diastolic, and mean arterial blood pressures in POST were lower than those in PRE (P = 0.006, P = 0.005, and P = 0.004). No significant differences in skin temperatures between PRE and POST were found for the cold tolerance test. There were no significant differences in energy expenditure during cold exposure between PRE and POST. Subjects felt less cold in POST than in PRE (P = 0.013) whereas there was no significant difference in overall thermal comfort between PRE and POST. These results suggest that cold adaptation can still occur in the presence of heat stress.
Collapse
Affiliation(s)
- Joonhee Park
- Research Institute of Human Ecology, Seoul National University, Seoul, Republic of Korea.
| | - Sora Shin
- College of Human Ecology, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea; Design School, Kyushu University, Fukuoka, Japan.
| | - Joo-Young Lee
- Research Institute of Human Ecology, Seoul National University, Seoul, Republic of Korea; College of Human Ecology, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea.
| |
Collapse
|
34
|
Schleh MW, Ruby BC, Dumke CL. Short term heat acclimation reduces heat stress, but is not augmented by dehydration. J Therm Biol 2018; 78:227-234. [DOI: 10.1016/j.jtherbio.2018.10.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 09/21/2018] [Accepted: 10/12/2018] [Indexed: 11/17/2022]
|
35
|
Gibson OR, Taylor L, Watt PW, Maxwell NS. Cross-Adaptation: Heat and Cold Adaptation to Improve Physiological and Cellular Responses to Hypoxia. Sports Med 2018; 47:1751-1768. [PMID: 28389828 PMCID: PMC5554481 DOI: 10.1007/s40279-017-0717-z] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
To prepare for extremes of heat, cold or low partial pressures of oxygen (O2), humans can undertake a period of acclimation or acclimatization to induce environment-specific adaptations, e.g. heat acclimation (HA), cold acclimation (CA), or altitude training. While these strategies are effective, they are not always feasible due to logistical impracticalities. Cross-adaptation is a term used to describe the phenomenon whereby alternative environmental interventions, e.g. HA or CA, may be a beneficial alternative to altitude interventions, providing physiological stress and inducing adaptations observable at altitude. HA can attenuate physiological strain at rest and during moderate-intensity exercise at altitude via adaptations allied to improved O2 delivery to metabolically active tissue, likely following increases in plasma volume and reductions in body temperature. CA appears to improve physiological responses to altitude by attenuating the autonomic response to altitude. While no cross-acclimation-derived exercise performance/capacity data have been measured following CA, post-HA improvements in performance underpinned by aerobic metabolism, and therefore dependent on O2 delivery at altitude, are likely. At a cellular level, heat shock protein responses to altitude are attenuated by prior HA, suggesting that an attenuation of the cellular stress response and therefore a reduced disruption to homeostasis at altitude has occurred. This process is known as cross-tolerance. The effects of CA on markers of cross-tolerance is an area requiring further investigation. Because much of the evidence relating to cross-adaptation to altitude has examined the benefits at moderate to high altitudes, future research examining responses at lower altitudes should be conducted, given that these environments are more frequently visited by athletes and workers. Mechanistic work to identify the specific physiological and cellular pathways responsible for cross-adaptation between heat and altitude, and between cold and altitude, is warranted, as is exploration of benefits across different populations and physical activity profiles.
Collapse
Affiliation(s)
- Oliver R Gibson
- Centre for Human Performance, Exercise and Rehabilitation (CHPER), Brunel University London, Uxbridge, UK. .,Welkin Human Performance Laboratories, Centre for Sport and Exercise Science and Medicine (SESAME), University of Brighton, Denton Road, Eastbourne, UK.
| | - Lee Taylor
- Athlete Health and Performance Research Centre, ASPETAR, Qatar Orthopaedic and Sports Medicine Hospital, Doha, Qatar.,School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK
| | - Peter W Watt
- Welkin Human Performance Laboratories, Centre for Sport and Exercise Science and Medicine (SESAME), University of Brighton, Denton Road, Eastbourne, UK
| | - Neil S Maxwell
- Welkin Human Performance Laboratories, Centre for Sport and Exercise Science and Medicine (SESAME), University of Brighton, Denton Road, Eastbourne, UK
| |
Collapse
|
36
|
Abstract
Background Although the acquisition of heat acclimation (HA) is well-documented, less is known about HA decay (HAD) and heat re-acclimation (HRA). The available literature suggests 1 day of HA is lost following 2 days of HAD. Understanding this relationship has the potential to impact upon the manner in which athletes prepare for major competitions, as a HA regimen may be disruptive during final preparations (i.e., taper). Objective The aim of this systematic review and meta-analysis was to determine the rate of HAD and HRA in three of the main physiological adaptations occurring during HA: heart rate (HR), core temperature (Tc), and sweat rate (SR). Data Sources Data for this systematic review were retrieved from Scopus and critical review of the cited references. Study Selection Studies were included when they met the following criteria: HA, HAD, and HRA (when available) were quantified in terms of exposure and duration. HA had to be for at least 5 days and HAD for at least 7 days for longitudinal studies. HR, Tc, or SR had to be monitored in human participants. Study Appraisal The level of bias in each study was assessed using the McMaster critical review form. Multiple linear regression techniques were used to determine the dependency of HAD in HR, Tc, and SR from the number of HA and HAD days, daily HA exposure duration, and intensity. Results Twelve studies met the criteria and were systematically reviewed. HAD was quantified as a percentage change relative to HA (0% = HA, 100% = unacclimated state). Adaptations in end-exercise HR decreased by 2.3% (P < 0.001) for every day of HAD. For end-exercise Tc, the daily decrease was 2.6% (P < 0.01). The adaptations in Tc during the HA period were more sustainable when the daily heat exposure duration was increased and heat exposure intensity decreased. The decay in SR was not related to the number of decay days. However, protracted HA-regimens seem to induce longer-lasting adaptations in SR. High heat exposure intensities during HA seem to evoke more sustained adaptations in SR than lower heat stress. Only eight studies investigated HRA. HRA was 8–12 times faster than HAD at inducing adaptations in HR and Tc, but no differences could be established for SR. Limitations The available studies lacked standardization in the protocols for HA and HAD. Conclusions HAD and HRA differ considerably between physiological systems. Five or more HA days are sufficient to cause adaptations in HR and Tc; however, extending the daily heat exposure duration enhances Tc adaptations. For every decay day, ~ 2.5% of the adaptations in HR and Tc are lost. For SR, longer HA periods are related to better adaptations. High heat exposure intensities seem beneficial for adaptations in SR, but not in Tc. HRA induces adaptations in HR and Tc at a faster rate than HA. HRA may thus provide a practical and less disruptive means of maintaining and optimizing HA prior to competition.
Collapse
Affiliation(s)
- Hein A M Daanen
- Department of Human Movement Sciences, Faculty of Behavioural and Movement Sciences, Amsterdam Movement Sciences, Vrije Universiteit Amsterdam, Van der Boechorststraat 7, 1081BT, Amsterdam, The Netherlands.
| | - Sebastien Racinais
- Athlete Health and Performance Research Centre, Aspetar Orthopaedic and Sports Medicine Hospital, Doha, Qatar
| | - Julien D Périard
- Athlete Health and Performance Research Centre, Aspetar Orthopaedic and Sports Medicine Hospital, Doha, Qatar
- Research Institute for Sport and Exercise, University of Canberra, Canberra, ACT, Australia
| |
Collapse
|
37
|
Pryor JL, Johnson EC, Roberts WO, Pryor RR. Application of evidence-based recommendations for heat acclimation: Individual and team sport perspectives. Temperature (Austin) 2018; 6:37-49. [PMID: 30906810 PMCID: PMC6422510 DOI: 10.1080/23328940.2018.1516537] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 06/28/2018] [Accepted: 06/28/2018] [Indexed: 01/18/2023] Open
Abstract
Heat acclimation or acclimatization (HA) occurs with repeated exposure to heat inducing adaptations that enhance thermoregulatory mechanisms and heat tolerance leading to improved exercise performance in warm-to-hot conditions. HA is an essential heat safety and performance enhancement strategy in preparation for competitions in warm-to-hot conditions for both individual and team sports. Yet, some data indicate HA is an underutilized pre-competition intervention in athletes despite the well-known benefits; possibly due to a lack of practical information provided to athletes and coaches. Therefore, the aim of this review is to provide actionable evidence-based implementation strategies and protocols to induce and sustain HA. We propose the following suggestions to circumvent potential implementation barriers: 1) incorporate multiple induction methods during the initial acclimation period, 2) complete HA 1-3 weeks before competition in the heat to avoid training and logistical conflicts during the taper period, and 3) minimize adaptation decay through intermittent exercise-heat exposure or re-acclimating immediately prior to competition with 2-4 consecutive days of exercise-heat training. Use of these strategies may be desirable or necessary to optimize HA induction and retention around existing training or logistical requirements.
Collapse
Affiliation(s)
- J. Luke Pryor
- Department of Kinesiology, California State University, Fresno, CA, USA
| | - Evan C. Johnson
- Division of Kinesiology & Health, University of Wyoming, Laramie, WY, USA
| | - William O. Roberts
- Department of Family Medicine and Community Health, University of Minnesota, Minneapolis, MN, USA
| | - Riana R. Pryor
- Department of Kinesiology, California State University, Fresno, CA, USA
| |
Collapse
|
38
|
Casadio JR, Kilding AE, Cotter JD, Laursen PB. From Lab to Real World: Heat Acclimation Considerations for Elite Athletes. Sports Med 2018; 47:1467-1476. [PMID: 28035584 DOI: 10.1007/s40279-016-0668-9] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
As major sporting events are often held in hot environments, increased interest in ways of optimally heat acclimating athletes to maximise performance has emerged. Heat acclimation involves repeated exercise sessions in hot conditions that induce physiological and thermoregulatory adaptations that attenuate heat-induced performance impairments. Current evidence-based guidelines for heat acclimation are clear, but the application of these recommendations is not always aligned with the time commitments and training priorities of elite athletes. Alternative forms of heat acclimation investigated include hot water immersion and sauna bathing, yet uncertainty remains around the efficacy of these methods for reducing heat-induced performance impairments, as well as how this form of heat stress may add to an athlete's overall training load. An understanding of how to optimally prescribe and periodise heat acclimation based on the performance determinants of a given event is limited, as is knowledge of how heat acclimation may affect the quality of concurrent training sessions. Finally, differences in individual athlete responses to heat acclimation need to be considered. This article addresses alternative methods of heat acclimation and heat exposure, explores gaps in literature around understanding the real world application of heat acclimation for athletes, and highlights specific athlete considerations for practitioners.
Collapse
Affiliation(s)
- Julia R Casadio
- Sports Performance Research Institute New Zealand (SPRINZ), School of Sport and Recreation, Auckland University of Technology, Auckland, New Zealand.
- High Performance Sport New Zealand, PO Box 302 563, North Harbour, Auckland, 0751, New Zealand.
| | - Andrew E Kilding
- Sports Performance Research Institute New Zealand (SPRINZ), School of Sport and Recreation, Auckland University of Technology, Auckland, New Zealand
| | - James D Cotter
- School of Physical Education, Sport and Exercise Sciences, University of Otago, Dunedin, New Zealand
| | - Paul B Laursen
- Sports Performance Research Institute New Zealand (SPRINZ), School of Sport and Recreation, Auckland University of Technology, Auckland, New Zealand
- High Performance Sport New Zealand, PO Box 302 563, North Harbour, Auckland, 0751, New Zealand
| |
Collapse
|
39
|
Hawley JA, Lundby C, Cotter JD, Burke LM. Maximizing Cellular Adaptation to Endurance Exercise in Skeletal Muscle. Cell Metab 2018; 27:962-976. [PMID: 29719234 DOI: 10.1016/j.cmet.2018.04.014] [Citation(s) in RCA: 98] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The application of molecular techniques to exercise biology has provided novel insight into the complexity and breadth of intracellular signaling networks involved in response to endurance-based exercise. Here we discuss several strategies that have high uptake by athletes and, on mechanistic grounds, have the potential to promote cellular adaptation to endurance training in skeletal muscle. Such approaches are based on the underlying premise that imposing a greater metabolic load and provoking extreme perturbations in cellular homeostasis will augment acute exercise responses that, when repeated over months and years, will amplify training adaptation.
Collapse
Affiliation(s)
- John A Hawley
- Exercise and Nutrition Research Program, Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC 3000, Australia.
| | - Carsten Lundby
- Centre for Physical Activity Research, Copenhagen University Hospital, Copenhagen, Denmark
| | - James D Cotter
- School of Physical Education, Sport and Exercise Sciences, University of Otago, Dunedin, New Zealand
| | - Louise M Burke
- Exercise and Nutrition Research Program, Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC 3000, Australia; Department of Sport Nutrition, Australian Institute of Sport, Belconnen, ACT, Australia
| |
Collapse
|
40
|
Willmott AGB, Gibson OR, James CA, Hayes M, Maxwell NS. Physiological and perceptual responses to exercising in restrictive heat loss attire with use of an upper-body sauna suit in temperate and hot conditions. Temperature (Austin) 2018; 5:162-174. [PMID: 30377634 DOI: 10.1080/23328940.2018.1426949] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 01/08/2018] [Indexed: 10/18/2022] Open
Abstract
The aim of this experiment was to quantify physiological and perceptual responses to exercise with and without restrictive heat loss attire in hot and temperate conditions. Ten moderately-trained individuals (mass; 69.44±7.50 kg, body fat; 19.7±7.6%) cycled for 30-mins (15-mins at 2 W.kg-1 then 15-mins at 1 W.kg-1) under four experimental conditions; temperate (TEMP, 22°C/45%), hot (HOT, 45°C/20%) and, temperate (TEMPSUIT, 22°C/45%) and hot (HOTSUIT, 45°C/20%) whilst wearing an upper-body "sauna suit". Core temperature changes were higher (P<0.05) in TEMPSUIT (+1.7±0.4°C.hr-1), HOT (+1.9±0.5°C.hr-1) and HOTSUIT (+2.3±0.5°C.hr-1) than TEMP (+1.3±0.3°C.hr-1). Skin temperature was higher (P<0.05) in HOT (36.53±0.93°C) and HOTSUIT (37.68±0.68°C) than TEMP (33.50±1.77°C) and TEMPSUIT (33.41±0.70°C). Sweat rate was greater (P<0.05) in TEMPSUIT (0.89±0.24 L.hr-1), HOT (1.14±0.48 L.hr-1) and HOTSUIT (1.51±0.52 L.hr-1) than TEMP (0.56±0.27 L.hr-1). Peak heart rate was higher (P<0.05) in TEMPSUIT (155±23 b.min-1), HOT (163±18 b.min-1) and HOTSUIT (171±18 b.min-1) than TEMP (151±20 b.min-1). Thermal sensation and perceived exertion were greater (P<0.05) in TEMPSUIT (5.8±0.5 and 14±1), HOT (6.4±0.5 and 15±1) and HOTSUIT (7.1±0.5 and 16±1) than TEMP (5.3±0.5 and 14±1). Exercising in an upper-body sauna suit within temperate conditions induces a greater physiological strain and evokes larger sweat losses compared to exercising in the same conditions, without restricting heat loss. In hot conditions, wearing a sauna suit increases physiological and perceptual strain further, which may accelerate the stimuli for heat adaptation and improve HA efficiency.
Collapse
Affiliation(s)
| | - Oliver R Gibson
- Environmental Extremes Laboratory, University of Brighton, Eastbourne, UK.,Centre for Human Performance, Exercise and Rehabilitation, Brunel University London, Uxbridge, UK
| | - Carl A James
- Environmental Extremes Laboratory, University of Brighton, Eastbourne, UK.,National Sports Institute, Institut Sukan Negara, National Sport Complex, Bukit Jalil, 57000 Kuala Lumpur, Malaysia
| | - Mark Hayes
- Environmental Extremes Laboratory, University of Brighton, Eastbourne, UK
| | - Neil S Maxwell
- Environmental Extremes Laboratory, University of Brighton, Eastbourne, UK
| |
Collapse
|
41
|
Ely BR, Clayton ZS, McCurdy CE, Pfeiffer J, Minson CT. Meta-inflammation and cardiometabolic disease in obesity: Can heat therapy help? Temperature (Austin) 2017; 5:9-21. [PMID: 29687041 PMCID: PMC5902218 DOI: 10.1080/23328940.2017.1384089] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 09/14/2017] [Accepted: 09/19/2017] [Indexed: 12/21/2022] Open
Abstract
Obesity and associated metabolic dysfunction have reached epidemic proportions worldwide. The current theory linking metabolic disease and obesity involves ischemic adipose tissue initiating an inflammatory cascade that results in systemic insulin resistance and may eventually lead to type II diabetes mellitus. Diabetes and associated metabolic dysfunction increase the risk of developing cardiovascular disease and fatal cardiovascular events. By targeting key steps in this process, ischemia and inflammation, this cascade may be prevented or reversed and thus metabolic and cardiovascular health may be preserved in obesity. Regular heat exposure (termed ‘heat therapy’) offers potential to improve cardiometabolic health in obese individuals through a variety of mechanisms that include but are not limited to heat shock proteins, hypoxia-inducible factor 1α, and hemodynamic effects. The purpose of this review is to highlight the cardiometabolic decline in obese individuals stemming from adipose tissue dysfunction, and examine the ways in which heat therapy and associated cellular and systemic adaptations can intersect with this decline in function to improve or restore cardiovascular and metabolic health.
Collapse
Affiliation(s)
- Brett R Ely
- Department of Human Physiology, University of Oregon, Eugene, OR, USA
| | - Zachary S Clayton
- Department of Human Physiology, University of Oregon, Eugene, OR, USA
| | - Carrie E McCurdy
- Department of Human Physiology, University of Oregon, Eugene, OR, USA
| | - Joshua Pfeiffer
- Peace Health Medical Group, Oregon Bariatric Center, Springfield, OR, USA
| | | |
Collapse
|
42
|
Heart rate variability and plasma nephrines in the evaluation of heat acclimatisation status. Eur J Appl Physiol 2017; 118:165-174. [PMID: 29127509 PMCID: PMC5754393 DOI: 10.1007/s00421-017-3758-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Accepted: 10/31/2017] [Indexed: 11/03/2022]
Abstract
Purpose Heat adaptation (HA) is critical to performance and health in a hot environment. Transition from short-term heat acclimatisation (STHA) to long-term heat acclimatisation (LTHA) is characterised by decreased autonomic disturbance and increased protection from thermal injury. A standard heat tolerance test (HTT) is recommended for validating exercise performance status, but any role in distinguishing STHA from LTHA is unreported. The aims of this study were to (1) define performance status by serial HTT during structured natural HA, (2) evaluate surrogate markers of autonomic activation, including heart rate variability (HRV), in relation to HA status. Methods Participants (n = 13) were assessed by HTT (60-min block-stepping, 50% VO2peak) during STHA (Day 2, 6 and 9) and LTHA (Day 23). Core temperature (Tc) and heart rate (HR) were measured every 5 min. Sampling for HRV indices (RMSSD, LF:HF) and sympathoadrenal blood measures (cortisol, nephrines) was undertaken before and after (POST) each HTT. Results Significant (P < 0.05) interactions existed for Tc, logLF:HF, cortisol and nephrines (two-way ANOVA; HTT by Day). Relative to LTHA, POST results differed significantly for Tc (Day 2, 6 and 9), HR (Day 2), logRMSSD (Day 2 and Day 6), logLF:HF (Day 2 and Day 6), cortisol (Day 2) and nephrines (Day 2 and Day 9). POST differences in HRV (Day 6 vs. 23) were + 9.9% (logRMSSD) and − 18.6% (logLF:HF). Conclusions Early reductions in HR and cortisol characterised STHA, whereas LTHA showed diminished excitability by Tc, HRV and nephrine measures. Measurement of HRV may have potential to aid real-time assessment of readiness for activity in the heat. Electronic supplementary material The online version of this article (10.1007/s00421-017-3758-y) contains supplementary material, which is available to authorized users.
Collapse
|
43
|
Lee BJ, Thake CD. Heat and Hypoxic Acclimation Increase Monocyte Heat Shock Protein 72 but Do Not Attenuate Inflammation following Hypoxic Exercise. Front Physiol 2017; 8:811. [PMID: 29085305 PMCID: PMC5650636 DOI: 10.3389/fphys.2017.00811] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2017] [Accepted: 10/02/2017] [Indexed: 12/11/2022] Open
Abstract
Acclimation to heat or hypoxic stress activates the heat shock response and accumulation of cytoprotective heat shock proteins (HSPs). By inhibiting the NF-κB pathway HSP72 can preserve epithelial function and reduce systemic inflammation. The aim of this study was to determine the time course of mHSP72 accumulation during acclimation, and to assess intestinal barrier damage and systemic inflammation following hypoxic exercise. Three groups completed 10 × 60-min acclimation sessions (50% normoxic VO2peak) in control (n = 7; 18°C, 35% RH), hypoxic (n = 7; FiO2 = 0.14, 18°C, 35% RH), or hot (n = 7; 40°C, 25% RH) conditions. Tumor necrosis factor-α (TNF-α), interleukin 6 (IL-6), interleukin 10 (IL-10), and intestinal fatty acid binding protein (I-FABP) were determined at rest and following a cycling normoxic stress test (NST; ~2 weeks before acclimation), pre-acclimation hypoxic stress test (HST1; FiO2 = 0.14, both at 50% normoxic VO2peak; ~1 week before acclimation) and post-acclimation HST (48 h; HST2). Monocyte HSP72 (mHSP72) was determined before and after exercise on day 1, 3, 5, 6, and 10 of acclimation. Accumulation of basal mHSP72 was evident from day 5 (p < 0.05) of heat acclimation and increased further on day 6 (p < 0.01), and day 10 (p < 0.01). In contrast, basal mHSP72 was elevated on the final day of hypoxic acclimation (p < 0.05). Following the NST, plasma TNF-α (–0.11 ± 0.27 ng.mL−1), IL-6 (+0.62 ± 0.67 ng.mL−1) IL-10 (+1.09 ± 9.06 ng.mL−1) and I-FABP (+37.6 ± 112.8 pg.mL−1) exhibited minimal change. After HST1, IL-6 (+3.87 ± 2.56 ng.mL−1), IL-10 (+26.15 ± 26.06 ng.mL−1) and I-FABP (+183.7 ± 182.1 pg.mL−1) were elevated (p < 0.01), whereas TNF-α was unaltered (+0.08 ± 1.27; p > 0.05). A similar trend was observed after HST2, with IL-6 (+3.09 ± 1.30 ng.mL−1), IL-10 (+23.22 ± 21.67 ng.mL−1) and I-FABP (+145.9 ±123.2 pg.mL−1) increased from rest. Heat acclimation induces mHSP72 accumulation earlier and at a greater magnitude compared to matched work hypoxic acclimation, however neither acclimation regime attenuated the systemic cytokine response or intestinal damage following acute exercise in hypoxia.
Collapse
Affiliation(s)
- Ben J Lee
- Occupational Performance Research Group, Department of Sport and Exercise Sciences, University of Chichester, Chichester, United Kingdom.,Centre for Applied Biological and Exercise Sciences, Coventry University, Coventry, United Kingdom
| | - Charles D Thake
- Occupational Performance Research Group, Department of Sport and Exercise Sciences, University of Chichester, Chichester, United Kingdom
| |
Collapse
|
44
|
Kim JM, Lim KS, Byun M, Lee KT, Yang YR, Park M, Lim D, Chai HH, Bang HT, Hwangbo J, Choi YH, Cho YM, Park JE. Identification of the acclimation genes in transcriptomic responses to heat stress of White Pekin duck. Cell Stress Chaperones 2017; 22:787-797. [PMID: 28634817 PMCID: PMC5655367 DOI: 10.1007/s12192-017-0809-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 05/10/2017] [Accepted: 05/15/2017] [Indexed: 12/14/2022] Open
Abstract
White Pekin duck is an important meat resource in the livestock industries. However, the temperature increase due to global warming has become a serious environmental factor in duck production, because of hyperthermia. Therefore, identifying the gene regulations and understanding the molecular mechanism for adaptation to the warmer environment will provide insightful information on the acclimation system of ducks. This study examined transcriptomic responses to heat stress treatments (3 and 6 h at 35 °C) and control (C, 25 °C) using RNA-sequencing analysis of genes from the breast muscle tissue. Based on three distinct differentially expressed gene (DEG) sets (3H/C, 6H/C, and 6H/3H), the expression patterns of significant DEGs (absolute log2 > 1.0 and false discovery rate < 0.05) were clustered into three responsive gene groups divided into upregulated and downregulated genes. Next, we analyzed the clusters that showed relatively higher expression levels in 3H/C and lower levels in 6H/C with much lower or opposite levels in 6H/3H; we referred to these clusters as the adaptable responsive gene group. These genes were significantly enriched in the ErbB signaling pathway, neuroactive ligand-receptor interaction and type II diabetes mellitus in the KEGG pathways (P < 0.01). From the functional enrichment analysis and significantly regulated genes observed in the enriched pathways, we think that the adaptable responsive genes are responsible for the acclimation mechanism of ducks and suggest that the regulation of phosphoinositide 3-kinase genes including PIK3R6, PIK3R5, and PIK3C2B has an important relationship with the mechanisms of adaptation to heat stress in ducks.
Collapse
Affiliation(s)
- Jun-Mo Kim
- Animal Genomics and Bioinformatics Division, National Institute of Animal Science, RDA, Wanju, 55365, Republic of Korea
| | - Kyu-Sang Lim
- Animal Genomics and Bioinformatics Division, National Institute of Animal Science, RDA, Wanju, 55365, Republic of Korea
| | - Mijeong Byun
- Animal Genomics and Bioinformatics Division, National Institute of Animal Science, RDA, Wanju, 55365, Republic of Korea
| | - Kyung-Tai Lee
- Animal Genomics and Bioinformatics Division, National Institute of Animal Science, RDA, Wanju, 55365, Republic of Korea
| | - Young-Rok Yang
- Institute of Agriculture and Life Sciences, Gyeongsang National University, Jinju, 52828, Republic of Korea
| | - Mina Park
- Animal Genomics and Bioinformatics Division, National Institute of Animal Science, RDA, Wanju, 55365, Republic of Korea
| | - Dajeong Lim
- Animal Genomics and Bioinformatics Division, National Institute of Animal Science, RDA, Wanju, 55365, Republic of Korea
| | - Han-Ha Chai
- Animal Genomics and Bioinformatics Division, National Institute of Animal Science, RDA, Wanju, 55365, Republic of Korea
| | - Han-Tae Bang
- Poultry Research Institute, National Institute of Animal Science, RDA, Pyeongchang, 25342, Republic of Korea
| | - Jong Hwangbo
- Poultry Research Institute, National Institute of Animal Science, RDA, Pyeongchang, 25342, Republic of Korea
| | - Yang-Ho Choi
- Institute of Agriculture and Life Sciences, Gyeongsang National University, Jinju, 52828, Republic of Korea
- Department of Animal Science, Gyeongsang National University, Jinju, 52828, Republic of Korea
| | - Yong-Min Cho
- Animal Genomics and Bioinformatics Division, National Institute of Animal Science, RDA, Wanju, 55365, Republic of Korea
| | - Jong-Eun Park
- Animal Genomics and Bioinformatics Division, National Institute of Animal Science, RDA, Wanju, 55365, Republic of Korea.
| |
Collapse
|
45
|
Bruchim Y, Horowitz M, Aroch I. Pathophysiology of heatstroke in dogs - revisited. Temperature (Austin) 2017; 4:356-370. [PMID: 29435477 PMCID: PMC5800390 DOI: 10.1080/23328940.2017.1367457] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Revised: 08/09/2017] [Accepted: 08/10/2017] [Indexed: 01/09/2023] Open
Abstract
Heatstroke results from a failure to dissipate accumulated heat during exposure to hot environments, or during strenuous physical exercise under heat stress. It is characterized by core body temperatures > 41°C, with central nervous system dysfunction. Functional morphology and thermoregulatory effectors differences between dogs and humans may require special heatstroke protective adaptations in dogs, however, the risk factors for developing heatstroke are similar in both. In dogs, these include hot, especially highly humid environments, excessive physical activity, obesity, large (>15 kg) body weight, being of certain breed (e.g., Labrador retrievers and brachycephalic breeds), upper airway obstruction and prolonged seizures. Lack of acclimation to heat and physical fitness decreases the survival of heat stroked dogs. At the systemic level, blood pooling within the large internal organs (e.g., spleen, liver) is a major contributor to the development of shock and consequent intestinal ischemia, hypoxia and endothelial hyperpermeability, commonly occurring in heatstroke patients. Evoked serious complications include rhabdomyolysis, acute kidney injury, acute respiratory distress syndrome and ultimately, sepsis and disseminated intravascular coagulation. The most common clinical signs in dogs include acute collapse, tachypnea, spontaneous bleeding, shock signs and mental abnormalities, including depression, disorientation or delirium, seizures, stupor and coma. In such dogs, presence of peripheral blood nucleated red blood cells uniquely occurs, and is a highly sensitive diagnostic and prognostic biomarker. Despite early, appropriate body cooling, and intensive supportive treatment, with no available specific treatment to ameliorate the severe inflammatory and hemostatic derangements, the mortality rate is around 50%, similar to that of human heatstroke victims. This review discusses the pathophysiology of canine heatstroke from a veterinarian's point of view, integrating new and old studies and knowledge.
Collapse
Affiliation(s)
- Yaron Bruchim
- The Hebrew University Veterinary Teaching Hospital and Koret School of Veterinary Medicine, The Hebrew University of Jerusalem
- Laboratory of Environmental Physiology, Hadassah Medical Center, The Hebrew University of Jerusalem
| | - Michal Horowitz
- Laboratory of Environmental Physiology, Hadassah Medical Center, The Hebrew University of Jerusalem
| | - Itamar Aroch
- The Hebrew University Veterinary Teaching Hospital and Koret School of Veterinary Medicine, The Hebrew University of Jerusalem
| |
Collapse
|
46
|
Horowitz M. Heat Acclimation-Mediated Cross-Tolerance: Origins in within-Life Epigenetics? Front Physiol 2017; 8:548. [PMID: 28804462 PMCID: PMC5532440 DOI: 10.3389/fphys.2017.00548] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2017] [Accepted: 07/14/2017] [Indexed: 12/29/2022] Open
Abstract
The primary outcome of heat acclimation is increased thermotolerance, which stems from enhancement of innate cytoprotective pathways. These pathways produce “ON CALL” molecules that can combat stressors to which the body has never been exposed, via cross-tolerance mechanisms (heat acclimation-mediated cross-tolerance—HACT). The foundation of HACT lies in the sharing of generic stress signaling, combined with tissue/organ- specific protective responses. HACT becomes apparent when acclimatory homeostasis is achieved, lasts for several weeks, and has a memory. HACT differs from other forms of temporal protective mechanisms activated by exposure to lower “doses” of the stressor, which induce adaptation to higher “doses” of the same/different stressor; e.g., preconditioning, hormesis. These terms have been adopted by biochemists, toxicologists, and physiologists to describe the rapid cellular strategies ensuring homeostasis. HACT employs two major protective avenues: constitutive injury attenuation and abrupt post-insult release of help signals enhanced by acclimation. To date, the injury-attenuating features seen in all organs studied include fast-responding, enlarged cytoprotective reserves with HSPs, anti-oxidative, anti-apoptotic molecules, and HIF-1α nuclear and mitochondrial target gene products. Using cardiac ischemia and brain hypoxia models as a guide to the broader framework of phenotypic plasticity, HACT is enabled by a metabolic shift induced by HIF-1α and there are less injuries caused by Ca+2 overload, via channel or complex-protein remodeling, or decreased channel abundance. Epigenetic markers such as post-translational histone modification and altered levels of chromatin modifiers during acclimation and its decline suggest that dynamic epigenetic mechanisms controlling gene expression induce HACT and acclimation memory, to enable the rapid return of the protected phenotype. In this review the link between in vivo physiological evidence and the associated cellular and molecular mechanisms leading to HACT and its difference from short-acting cross-tolerance strategies will be discussed.
Collapse
Affiliation(s)
- Michal Horowitz
- Laboratory of Environmental Physiology, Faculty of Dentistry, Hebrew University of JerusalemJerusalem, Israel
| |
Collapse
|
47
|
Tuttle JA, Chrismas BCR, Gibson OR, Barrington JH, Hughes DC, Castle PC, Metcalfe AJ, Midgley AW, Pearce O, Kabir C, Rayanmarakar F, Al-Ali S, Lewis MP, Taylor L. The Hsp72 and Hsp90α mRNA Responses to Hot Downhill Running Are Reduced Following a Prior Bout of Hot Downhill Running, and Occur Concurrently within Leukocytes and the Vastus Lateralis. Front Physiol 2017; 8:473. [PMID: 28747888 PMCID: PMC5506191 DOI: 10.3389/fphys.2017.00473] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 06/21/2017] [Indexed: 12/14/2022] Open
Abstract
The leukocyte heat shock response (HSR) is used to determine individual's thermotolerance. The HSR and thermotolerance are enhanced following interventions such as preconditioning and/or acclimation/acclimatization. However, it is unclear whether the leukocyte HSR is an appropriate surrogate for the HSR in other tissues implicated within the pathophysiology of exertional heat illnesses (e.g., skeletal muscle), and whether an acute preconditioning strategy (e.g., downhill running) can improve subsequent thermotolerance. Physically active, non-heat acclimated participants were split into two groups to investigate the benefits of hot downhill running as preconditioning strategy. A hot preconditioning group (HPC; n = 6) completed two trials (HPC1HOTDOWN and HPC2HOTDOWN) of 30 min running at lactate threshold (LT) on -10% gradient in 30°C and 50% relative humidity (RH) separated by 7 d. A temperate preconditioning group (TPC; n = 5) completed 30 min running at LT on a -1% gradient in 20°C and 50% (TPC1TEMPFLAT) and 7 d later completed 30 min running at LT on -10% gradient in 30°C and 50% RH (TPC2HOTDOWN). Venous blood samples and muscle biopsies (vastus lateralis; VL) were obtained before, immediately after, 3, 24, and 48 h after each trial. Leukocyte and VL Hsp72, Hsp90α, and Grp78 mRNA relative expression was determined via RT-QPCR. Attenuated leukocyte and VL Hsp72 (2.8 to 1.8 fold and 5.9 to 2.4 fold; p < 0.05) and Hsp90α mRNA (2.9 to 2.4 fold and 5.2 to 2.4 fold; p < 0.05) responses accompanied reductions (p < 0.05) in physiological strain [exercising rectal temperature (-0.3°C) and perceived muscle soreness (~ -14%)] during HPC2HOTDOWN compared to HPC1HOTDOWN (i.e., a preconditioning effect). Both VL and leukocyte Hsp72 and Hsp90α mRNA increased (p < 0.05) simultaneously following downhill runs and demonstrated a strong relationship (p < 0.01) of similar magnitudes with one another. Hot downhill running is an effective preconditioning strategy which ameliorates physiological strain, soreness and Hsp72 and Hsp90α mRNA responses to a subsequent bout. Leukocyte and VL analyses are appropriate tissues to infer the extent to which the HSR has been augmented.
Collapse
Affiliation(s)
- James A Tuttle
- Muscle Cellular and Molecular Physiology Research Group, Department of Sport Science and Physical Activity, Institute of Sport and Physical Activity Research, University of BedfordshireBedford, United Kingdom
| | - Bryna C R Chrismas
- Sport Science Program, College of Arts and Sciences, Qatar UniversityDoha, Qatar
| | - Oliver R Gibson
- Centre for Human Performance, Exercise and Rehabilitation, Division of Sport, Health and Exercise Sciences, Department of Life Sciences, Brunel University LondonLondon, United Kingdom
| | - James H Barrington
- Muscle Cellular and Molecular Physiology Research Group, Department of Sport Science and Physical Activity, Institute of Sport and Physical Activity Research, University of BedfordshireBedford, United Kingdom
| | - David C Hughes
- Department of Neurobiology, Physiology and Behavior, University of California, DavisDavis, CA, United States
| | - Paul C Castle
- Muscle Cellular and Molecular Physiology Research Group, Department of Sport Science and Physical Activity, Institute of Sport and Physical Activity Research, University of BedfordshireBedford, United Kingdom
| | - Alan J Metcalfe
- Muscle Cellular and Molecular Physiology Research Group, Department of Sport Science and Physical Activity, Institute of Sport and Physical Activity Research, University of BedfordshireBedford, United Kingdom.,School of Exercise and Health Sciences, Edith Cowan UniversityPerth, WA, Australia
| | - Adrian W Midgley
- Department of Sport and Physical Activity, Edgehill UniversityOrmskirk, United Kingdom
| | - Oliver Pearce
- Milton Keynes University HospitalMilton Keynes, United Kingdom
| | - Chindu Kabir
- Milton Keynes University HospitalMilton Keynes, United Kingdom
| | | | - Sami Al-Ali
- Milton Keynes University HospitalMilton Keynes, United Kingdom
| | - Mark P Lewis
- National Centre for Sport and Exercise Medicine, School of Sport, Exercise and Health Sciences, Loughborough UniversityLoughborough, United Kingdom.,School of Sport, Exercise and Health Sciences, Loughborough UniversityLoughborough, United Kingdom
| | - Lee Taylor
- School of Sport, Exercise and Health Sciences, Loughborough UniversityLoughborough, United Kingdom.,ASPETAR, Qatar Orthopedic and Sports Medicine HospitalDoha, Qatar
| |
Collapse
|
48
|
Influence of leptin and GABA B-receptor agonist and antagonist on neurons of the hypothalamic infundibular nucleus in the chicken. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2017; 203:291-299. [PMID: 28361168 DOI: 10.1007/s00359-017-1168-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Revised: 02/27/2017] [Accepted: 03/19/2017] [Indexed: 12/24/2022]
Abstract
In birds and mammals, the neuroendocrine regulation of energy balance is conserved in many aspects. Despite significant similarities between the two groups, differences in the regulatory mechanisms were detected. The present study was performed to carry out investigations of the influence of human leptin and GABAB-receptor agonist and antagonist on the firing rate of neurons of the Nucleus infundibuli hypothalami in brain slices from juvenile chickens. For the first time, we demonstrated a clear, dose-related change in the firing rate of hypothalamic neurons in juvenile chickens after the acute application of recombinant human leptin (1, 10, and 100 nM). All investigated neurons increased their subsequent firing rate. Application of GABAB-receptor agonist baclofen (1 µM) blocked, while antagonist CGP 35348 (10 µM) increased the spontaneous neuronal activity. Simultaneous application of baclofen and leptin reduced the effect observed from single leptin application. This was not found after simultaneously application of leptin and CGP. Altogether, our results indicate that in bird brain slices, and exemplarily in those of the chicken, hypothalamic neurons show mammalian-like responsiveness after acute leptin and GABA application. GABAB-mechanisms involved in GABA release play a likely important role in the leptin-mediated effects on NI neurons via functional leptin receptors.
Collapse
|
49
|
Alexander-Shani R, Mreisat A, Smeir E, Gerstenblith G, Stern MD, Horowitz M. Long-term HIF-1α transcriptional activation is essential for heat-acclimation-mediated cross tolerance: mitochondrial target genes. Am J Physiol Regul Integr Comp Physiol 2017; 312:R753-R762. [PMID: 28274939 DOI: 10.1152/ajpregu.00461.2016] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 03/01/2017] [Accepted: 03/03/2017] [Indexed: 11/22/2022]
Abstract
An important adaptive feature of heat acclimation (HA) is the induction of cross tolerance against novel stressors (HACT) Reprogramming of gene expression leading to enhanced innate cytoprotective features by attenuating damage and/or enhancing the response of "help" signals plays a pivotal role. Hypoxia-inducible factor-1α (HIF-1α), constitutively upregulated by HA (1 mo, 34°C), is a crucial transcription factor in this program, although its specific role is as yet unknown. By using a rat HA model, we studied the impact of disrupting HIF-1α transcriptional activation [HIF-1α:HIF-1β dimerization blockade by intraperitoneal acriflavine (4 mg/kg)] on its mitochondrial gene targets [phosphoinositide-dependent kinase-1 (PDK1), LON, and cyclooxygenase 4 (COX4) isoforms] in the HA rat heart. Physiological measures of cardiac HACT were infarct size after ischemia-reperfusion and time to rigor contracture during hypoxia in cardiomyocytes. We show that HACT requires transcriptional activation of HIF-1α throughout the course of HA and that this activation is accompanied by two metabolic switches: 1) profound upregulation of PDK1, which reduces pyruvate entry into the mitochondria, consequently increasing glycolytic lactate production; 2) remodeling of the COX4 isoform ratio, inducing hypoxic-tolerant COX4.2 dominance, and optimizing electron transfer and possibly ATP production during the ischemic and hypoxic insults. LON and COX4.2 transcript upregulation accompanied this shift. Loss of HACT despite elevated expression of the cytoprotective protein heat shock protein-72 concomitantly with disrupted HIF-1α dimerization suggests that HIF-1α is essential for HACT. The role of a PDK1 metabolic switch is well known in hypoxia acclimation but not in the HA model and its ischemic setting. Remodeling of COX4 isoforms by environmental acclimation is a novel finding.
Collapse
Affiliation(s)
- Rivka Alexander-Shani
- Laboratory of Environmental Physiology, Faculty of Dental Medicine, The Hebrew University, Jerusalem, Israel
| | - Ahmad Mreisat
- Laboratory of Environmental Physiology, Faculty of Dental Medicine, The Hebrew University, Jerusalem, Israel
| | - Elia Smeir
- Laboratory of Environmental Physiology, Faculty of Dental Medicine, The Hebrew University, Jerusalem, Israel
| | | | - Michael D Stern
- Gerontology Research Center, National Institute on Aging, Baltimore, Maryland
| | - Michal Horowitz
- Laboratory of Environmental Physiology, Faculty of Dental Medicine, The Hebrew University, Jerusalem, Israel;
| |
Collapse
|
50
|
Affiliation(s)
- Michal Horowitz
- Laboratory of Environmental Physiology Faculty of Dental Medicine The Hebrew University, Jerusalem 91120, Israel
| |
Collapse
|