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Fischer S, Nägeli K, Cardone D, Filippini C, Merla A, Hanusch KU, Ehlert U. Emerging effects of temperature on human cognition, affect, and behaviour. Biol Psychol 2024; 189:108791. [PMID: 38599369 DOI: 10.1016/j.biopsycho.2024.108791] [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: 08/14/2023] [Revised: 02/26/2024] [Accepted: 04/02/2024] [Indexed: 04/12/2024]
Abstract
Human body core temperature is tightly regulated within approximately 37 °C. Global near surface temperature has increased by over 1.2 °C between 1850 and 2020. In light of the challenge this poses to human thermoregulation, the present perspective article sought to provide an overview on the effects of varying ambient and body temperature on cognitive, affective, and behavioural domains of functioning. To this end, an overview of observational and experimental studies in healthy individuals and individuals with mental disorders was provided. Within body core temperature at approximately 37 °C, relatively lower ambient and skin temperatures appear to evoke a need for social connection, whereas comparably higher temperatures appear to facilitate notions of other as closer and more sociable. Above-average ambient temperatures are associated with increased conflicts as well as incident psychotic and depressive symptoms, mental disorders, and suicide. With mild hypo- and hyperthermia, paradoxical effects are observed: whereas the acute states are generally characterised by impairments in cognitive performance, anxiety, and irritability, individuals with depression experience longer-term symptom improvements with treatments deliberately inducing these states for brief amounts of time. When taken together, it has thus become clear that temperature is inexorably associated with human cognition, affect, and (potentially) behaviour. Given the projected increase in global warming, further research into the affective and behavioural sequelae of heat and the mechanisms translating it into mental health outcomes is urgently warranted.
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Affiliation(s)
- Susanne Fischer
- University of Zurich, Institute of Psychology, Zurich, Switzerland.
| | - Kathrin Nägeli
- University of Zurich, Department of Geography, Zurich, Switzerland
| | - Daniela Cardone
- University G. d'Annunzio of Chieti-Pescara, Department of Engineering and Geology, Chieti, Italy
| | - Chiara Filippini
- University G. d'Annunzio of Chieti-Pescara, Department of Engineering and Geology, Chieti, Italy
| | - Arcangelo Merla
- University G. d'Annunzio of Chieti-Pescara, Department of Engineering and Geology, Chieti, Italy
| | - Kay-Uwe Hanusch
- Bern University of Applied Sciences, Department of Health Sciences, Berne, Switzerland
| | - Ulrike Ehlert
- University of Zurich, Institute of Psychology, Zurich, Switzerland
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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.
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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.
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Notley SR, Mitchell D, Taylor NAS. A century of exercise physiology: concepts that ignited the study of human thermoregulation. Part 3: Heat and cold tolerance during exercise. Eur J Appl Physiol 2024; 124:1-145. [PMID: 37796292 DOI: 10.1007/s00421-023-05276-3] [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: 01/26/2023] [Accepted: 07/04/2023] [Indexed: 10/06/2023]
Abstract
In this third installment of our four-part historical series, we evaluate contributions that shaped our understanding of heat and cold stress during occupational and athletic pursuits. Our first topic concerns how we tolerate, and sometimes fail to tolerate, exercise-heat stress. By 1900, physical activity with clothing- and climate-induced evaporative impediments led to an extraordinarily high incidence of heat stroke within the military. Fortunately, deep-body temperatures > 40 °C were not always fatal. Thirty years later, water immersion and patient treatments mimicking sweat evaporation were found to be effective, with the adage of cool first, transport later being adopted. We gradually acquired an understanding of thermoeffector function during heat storage, and learned about challenges to other regulatory mechanisms. In our second topic, we explore cold tolerance and intolerance. By the 1930s, hypothermia was known to reduce cutaneous circulation, particularly at the extremities, conserving body heat. Cold-induced vasodilatation hindered heat conservation, but it was protective. Increased metabolic heat production followed, driven by shivering and non-shivering thermogenesis, even during exercise and work. Physical endurance and shivering could both be compromised by hypoglycaemia. Later, treatments for hypothermia and cold injuries were refined, and the thermal after-drop was explained. In our final topic, we critique the numerous indices developed in attempts to numerically rate hot and cold stresses. The criteria for an effective thermal stress index were established by the 1930s. However, few indices satisfied those requirements, either then or now, and the surviving indices, including the unvalidated Wet-Bulb Globe-Thermometer index, do not fully predict thermal strain.
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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.
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Notley SR, Mitchell D, Taylor NAS. A century of exercise physiology: concepts that ignited the study of human thermoregulation. Part 2: physiological measurements. Eur J Appl Physiol 2023; 123:2587-2685. [PMID: 37796291 DOI: 10.1007/s00421-023-05284-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 07/14/2023] [Indexed: 10/06/2023]
Abstract
In this, the second of four historical reviews on human thermoregulation during exercise, we examine the research techniques developed by our forebears. We emphasise calorimetry and thermometry, and measurements of vasomotor and sudomotor function. Since its first human use (1899), direct calorimetry has provided the foundation for modern respirometric methods for quantifying metabolic rate, and remains the most precise index of whole-body heat exchange and storage. Its alternative, biophysical modelling, relies upon many, often dubious assumptions. Thermometry, used for >300 y to assess deep-body temperatures, provides only an instantaneous snapshot of the thermal status of tissues in contact with any thermometer. Seemingly unbeknownst to some, thermal time delays at some surrogate sites preclude valid measurements during non-steady state conditions. To assess cutaneous blood flow, immersion plethysmography was introduced (1875), followed by strain-gauge plethysmography (1949) and then laser-Doppler velocimetry (1964). Those techniques allow only local flow measurements, which may not reflect whole-body blood flows. Sudomotor function has been estimated from body-mass losses since the 1600s, but using mass losses to assess evaporation rates requires precise measures of non-evaporated sweat, which are rarely obtained. Hygrometric methods provide data for local sweat rates, but not local evaporation rates, and most local sweat rates cannot be extrapolated to reflect whole-body sweating. The objective of these methodological overviews and critiques is to provide a deeper understanding of how modern measurement techniques were developed, their underlying assumptions, and the strengths and weaknesses of the measurements used for humans exercising and working in thermally challenging conditions.
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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
- College of Human Ecology, Research Institute of Human Ecology, Seoul National University, Seoul, Republic of Korea.
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Fernández-Peña C, Reimúndez A, Viana F, Arce VM, Señarís R. Sex differences in thermoregulation in mammals: Implications for energy homeostasis. Front Endocrinol (Lausanne) 2023; 14:1093376. [PMID: 36967809 PMCID: PMC10030879 DOI: 10.3389/fendo.2023.1093376] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Accepted: 02/06/2023] [Indexed: 03/10/2023] Open
Abstract
Thermal homeostasis is a fundamental process in mammals, which allows the maintenance of a constant internal body temperature to ensure an efficient function of cells despite changes in ambient temperature. Increasing evidence has revealed the great impact of thermoregulation on energy homeostasis. Homeothermy requires a fine regulation of food intake, heat production, conservation and dissipation and energy expenditure. A great interest on this field of research has re-emerged following the discovery of thermogenic brown adipose tissue and browning of white fat in adult humans, with a potential clinical relevance on obesity and metabolic comorbidities. However, most of our knowledge comes from male animal models or men, which introduces unwanted biases on the findings. In this review, we discuss how differences in sex-dependent characteristics (anthropometry, body composition, hormonal regulation, and other sexual factors) influence numerous aspects of thermal regulation, which impact on energy homeostasis. Individuals of both sexes should be used in the experimental paradigms, considering the ovarian cycles and sexual hormonal regulation as influential factors in these studies. Only by collecting data in both sexes on molecular, functional, and clinical aspects, we will be able to establish in a rigorous way the real impact of thermoregulation on energy homeostasis, opening new avenues in the understanding and treatment of obesity and metabolic associated diseases.
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Affiliation(s)
| | - Alfonso Reimúndez
- Department of Physiology, CIMUS, University of Santiago de Compostela, Santiago de Compostela, Spain
| | - Félix Viana
- Institute of Neuroscience, University Miguel Hernández (UMH)-CSIC, Alicante, Spain
| | - Victor M. Arce
- Department of Physiology, CIMUS, University of Santiago de Compostela, Santiago de Compostela, Spain
- *Correspondence: Rosa Señarís, ; Victor M. Arce,
| | - Rosa Señarís
- Department of Physiology, CIMUS, University of Santiago de Compostela, Santiago de Compostela, Spain
- *Correspondence: Rosa Señarís, ; Victor M. Arce,
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Zakic T, Stojanovic S, Jankovic A, Korac A, Pekovic-Vaughan V, Korac B. Redox-metabolic reprogramming of skin in mice lacking functional Nrf2 under basal conditions and cold acclimation. Biofactors 2022. [PMID: 36585756 DOI: 10.1002/biof.1931] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Accepted: 12/14/2022] [Indexed: 01/01/2023]
Abstract
Adaptive responses to environmental and physiological challenges, including exposure to low environmental temperature, require extensive structural, redox, and metabolic reprogramming. Detailed molecular mechanisms of such processes in the skin are lacking, especially the role of nuclear factor erythroid 2-related factor 2 (Nrf2) and other closely related redox-sensitive transcription factors Nrf1, Nrf3, and nuclear respiratory factor (NRF1). To investigate the role of Nrf2, we examined redox and metabolic responses in the skin of wild-type (WT) mice and mice lacking functional Nrf2 (Nrf2 KO) at room (RT, 24 ± 1°C) and cold (4 ± 1°C) temperature. Our results demonstrate distinct expression profiles of major enzymes involved in antioxidant defense and key metabolic and mitochondrial pathways in the skin, depending on the functional Nrf2 and/or cold stimulus. Nrf2 KO mice at RT displayed profound alterations in redox, mitochondrial and metabolic responses, generally akin to cold-induced skin responses in WT mice. Immunohistochemical analyses of skin cell compartments (keratinocytes, fibroblasts, hair follicle, and sebaceous gland) and spatial locations (nucleus and cytoplasm) revealed synergistic interactions between members of the Nrf transcription factor family as part of redox-metabolic reprogramming in WT mice upon cold acclimation. In contrast, Nrf2 KO mice at RT showed loss of NRF1 expression and a compensatory activation of Nrf1/Nrf3, which was abolished upon cold, concomitant with blunted redox-metabolic responses. These data show for the first time a novel role for Nrf2 in skin physiology in response to low environmental temperature, with important implications in human connective tissue diseases with altered thermogenic responses.
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Affiliation(s)
- Tamara Zakic
- Institute for Biological Research "Sinisa Stankovic"-National Institute of Republic of Serbia, University of Belgrade, Belgrade, Serbia
| | - Sara Stojanovic
- Faculty of Biology, University of Belgrade, Belgrade, Serbia
| | - Aleksandra Jankovic
- Institute for Biological Research "Sinisa Stankovic"-National Institute of Republic of Serbia, University of Belgrade, Belgrade, Serbia
| | | | - Vanja Pekovic-Vaughan
- Institute of Life Course and Medical Sciences, Faculty of Health and Life Sciences, University of Liverpool, Liverpool, UK
| | - Bato Korac
- Institute for Biological Research "Sinisa Stankovic"-National Institute of Republic of Serbia, University of Belgrade, Belgrade, Serbia
- Faculty of Biology, University of Belgrade, Belgrade, Serbia
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Damasceno JR, Cavalcante TF, Ferreira JEDSM, Barbosa EDS, Moreira RP, Lopes MVDO, Lira ALBDC. Accuracy of the defining characteristics of the nursing diagnosis hypothermia in patients on hemodialysis. Rev Bras Enferm 2022; 75:e20210620. [DOI: 10.1590/0034-7167-2021-0620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 01/01/2022] [Indexed: 11/22/2022] Open
Abstract
ABSTRACT Objective: to analyze the accuracy of the defining characteristics of hypothermia in patients on hemodialysis. Methods: a diagnostic accuracy study was assembled within a cross-sectional study with 124 patients from two dialysis centers. A latent class model was used for data analysis. Results: the nursing diagnosis hypothermia was present in 13 (10.48%) study participants. The most prevalent defining characteristics were hypoxia (100%), decrease in blood glucose level (83.1%), hypertension (65.3%), piloerection (45.2%), and skin cool to touch (41.1%). The defining characteristics acrocyanosis (99.96%) and cyanotic nail beds (99.98%) had a high sensitivity. Acrocyanosis (91.8%), skin cool to touch (64.8%), and peripheral vasoconstriction (91.8%) had high specificity. Conclusion: specific and sensitive indicators of hypothermia work as good clinical indicators for confirming this diagnosis in patients on hemodialysis. The study findings can assist nurses in their clinical reasoning for a correct inference of hypothermia.
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Verduzco-Mendoza A, Bueno-Nava A, Wang D, Martínez-Burnes J, Olmos-Hernández A, Casas A, Domínguez A, Mota-Rojas D. Experimental Applications and Factors Involved in Validating Thermal Windows Using Infrared Thermography to Assess the Health and Thermostability of Laboratory Animals. Animals (Basel) 2021; 11:3448. [PMID: 34944225 PMCID: PMC8698170 DOI: 10.3390/ani11123448] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 11/25/2021] [Accepted: 12/01/2021] [Indexed: 12/12/2022] Open
Abstract
Evaluating laboratory animals' health and thermostability are fundamental components of all experimental designs. Alterations in either one of these parameters have been shown to trigger physiological changes that can compromise the welfare of the species and the replicability and robustness of the results obtained. Due to the nature and complexity of evaluating and managing the species involved in research protocols, non-invasive tools such as infrared thermography (IRT) have been adopted to quantify these parameters without altering them or inducing stress responses in the animals. IRT technology makes it possible to quantify changes in surface temperatures that are derived from alterations in blood flow that can result from inflammatory, stressful, or pathological processes; changes can be measured in diverse regions, called thermal windows, according to their specific characteristics. The principal body regions that were employed for this purpose in laboratory animals were the orbital zone (regio orbitalis), auricular pavilion (regio auricularis), tail (cauda), and the interscapular area (regio scapularis). However, depending on the species and certain external factors, the sensitivity and specificity of these windows are still subject to controversy due to contradictory results published in the available literature. For these reasons, the objectives of the present review are to discuss the neurophysiological mechanisms involved in vasomotor responses and thermogenesis via BAT in laboratory animals and to evaluate the scientific usefulness of IRT and the thermal windows that are currently used in research involving laboratory animals.
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Affiliation(s)
- Antonio Verduzco-Mendoza
- PhD Program in Biological and Health Sciences [Doctorado en Ciencias Biológicas y de la Salud], Universidad Autónoma Metropolitana, Mexico City 04960, Mexico;
| | - Antonio Bueno-Nava
- División of Neurosciences, Instituto Nacional de Rehabilitación-Luis Guillermo Ibarra Ibarra, (INR-LGII), Mexico City 14389, Mexico;
| | - Dehua Wang
- School of Life Sciences, Shandong University, Qingdao 266237, China;
| | - Julio Martínez-Burnes
- Animal Health Group, Facultad de Medicina Veterinaria y Zootecnia, Universidad Autónoma de Tamaulipas, Victoria City 87000, Mexico;
| | - Adriana Olmos-Hernández
- Division of Biotechnology—Bioterio and Experimental Surgery, Instituto Nacional de Rehabilitación-Luis Guillermo Ibarra Ibarra (INR-LGII), Mexico City 14389, Mexico;
| | - Alejandro Casas
- Neurophysiology, Behavior and Animal Welfare Assessment, DPAA, Xochimilco Campus, Universidad Autónoma Metropolitana (UAM), Mexico City 04960, Mexico; (A.C.); (A.D.)
| | - Adriana Domínguez
- Neurophysiology, Behavior and Animal Welfare Assessment, DPAA, Xochimilco Campus, Universidad Autónoma Metropolitana (UAM), Mexico City 04960, Mexico; (A.C.); (A.D.)
| | - Daniel Mota-Rojas
- Neurophysiology, Behavior and Animal Welfare Assessment, DPAA, Xochimilco Campus, Universidad Autónoma Metropolitana (UAM), Mexico City 04960, Mexico; (A.C.); (A.D.)
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Greenfield AM, Charkoudian N, Alba BK. Influences of ovarian hormones on physiological responses to cold in women. Temperature (Austin) 2021; 9:23-45. [DOI: 10.1080/23328940.2021.1953688] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Affiliation(s)
- Andrew Martin Greenfield
- Thermal & Mountain Medicine Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA
- Oak Ridge Institute of Science and Education, Belcamp, MD, USA
| | - Nisha Charkoudian
- Thermal & Mountain Medicine Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - Billie Katherine Alba
- Thermal & Mountain Medicine Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA
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10
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Chen WC, Liu YB, Liu WF, Zhou YY, He HF, Lin S. Neuropeptide Y Is an Immunomodulatory Factor: Direct and Indirect. Front Immunol 2020; 11:580378. [PMID: 33123166 PMCID: PMC7573154 DOI: 10.3389/fimmu.2020.580378] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 09/18/2020] [Indexed: 12/12/2022] Open
Abstract
Neuropeptide Y (NPY), which is widely distributed in the nervous system, is involved in regulating a variety of biological processes, including food intake, energy metabolism, and emotional expression. However, emerging evidence points to NPY also as a critical transmitter between the nervous system and immune system, as well as a mediator produced and released by immune cells. In vivo and in vitro studies based on gene-editing techniques and specific NPY receptor agonists and antagonists have demonstrated that NPY is responsible for multifarious direct modulations on immune cells by acting on NPY receptors. Moreover, via the central or peripheral nervous system, NPY is closely connected to body temperature regulation, obesity development, glucose metabolism, and emotional expression, which are all immunomodulatory factors for the immune system. In this review, we focus on the direct role of NPY in immune cells and particularly discuss its indirect impact on the immune response.
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Affiliation(s)
- Wei-Can Chen
- Department of Anesthesiology, The Second Affiliated Hospital, Fujian Medical University, Quanzhou, China
| | - Yi-Bin Liu
- Department of Anesthesiology, The Second Affiliated Hospital, Fujian Medical University, Quanzhou, China
| | - Wei-Feng Liu
- Department of Anesthesiology, The Second Affiliated Hospital, Fujian Medical University, Quanzhou, China
| | - Ying-Ying Zhou
- Department of Anesthesiology, The Second Affiliated Hospital, Fujian Medical University, Quanzhou, China
| | - He-Fan He
- Department of Anesthesiology, The Second Affiliated Hospital, Fujian Medical University, Quanzhou, China
| | - Shu Lin
- Department of Anesthesiology, The Second Affiliated Hospital, Fujian Medical University, Quanzhou, China.,Centre of Neurological and Metabolic Research, The Second Affiliated Hospital, Fujian Medical University, Quanzhou, China.,Diabetes and Metabolism Division, Garvan Institute of Medical Research, Sydney, NSW, Australia
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11
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Arnold JT, Lloyd AB, Bailey SJ, Fujimoto T, Matsutake R, Takayanagi M, Nishiyasu T, Fujii N. The nitric oxide dependence of cutaneous microvascular function to independent and combined hypoxic cold exposure. J Appl Physiol (1985) 2020; 129:947-956. [DOI: 10.1152/japplphysiol.00487.2020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
When separated from local cooling, whole body cooling elicited cutaneous reflex vasoconstriction via mechanisms independent of nitric oxide removal. Hypoxia elicited cutaneous vasodilatation via mechanisms mediated primarily by nitric oxide synthase, rather than xanthine oxidase-mediated nitrite reduction. Cold-induced vasoconstriction was blunted by the opposing effect of hypoxic vasodilatation, whereas the underpinning mechanisms did not interrelate in the absence of local cooling. Full vasoconstriction was restored with nitric oxide synthase inhibition.
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Affiliation(s)
- Josh T. Arnold
- Environmental Ergonomics Research Centre, Loughborough University, Loughborough, United Kingdom
| | - Alex B. Lloyd
- Environmental Ergonomics Research Centre, Loughborough University, Loughborough, United Kingdom
| | - Stephen J. Bailey
- School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, United Kingdom
| | - Tomomi Fujimoto
- Department of Health and Sports, Niigata University of Health and Welfare, Niigata, Japan
- Institute for Human Movement and Medical Science, Niigata University of Health and Welfare, Niigata, Japan
- Faculty of Health and Sport Sciences, University of Tsukuba, Tsukuba, Japan
| | - Ryoko Matsutake
- Faculty of Health and Sport Sciences, University of Tsukuba, Tsukuba, Japan
| | | | - Takeshi Nishiyasu
- Faculty of Health and Sport Sciences, University of Tsukuba, Tsukuba, Japan
| | - Naoto Fujii
- Faculty of Health and Sport Sciences, University of Tsukuba, Tsukuba, Japan
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12
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Mugele H, Oliver SJ, Gagnon D, Lawley JS. Integrative crosstalk between hypoxia and the cold: Old data and new opportunities. Exp Physiol 2020; 106:350-358. [DOI: 10.1113/ep088512] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 06/25/2020] [Indexed: 12/20/2022]
Affiliation(s)
- Hendrik Mugele
- Department of Sport Science University of Innsbruck Innsbruck Austria
| | - Samuel J. Oliver
- Extremes Research Group School of Sport, Health and Exercise Sciences Bangor University Wales UK
| | - Daniel Gagnon
- Cardiovascular Prevention and Rehabilitation Centre Montreal Heart Institute Montréal Quebec Canada
- Department of Pharmacology and Physiology Faculty of Medicine Université de Montréal Montréal Quebec Canada
| | - Justin S. Lawley
- Department of Sport Science University of Innsbruck Innsbruck Austria
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Flavahan S, Flavahan NA. Cooling-induced dilatation of cutaneous arteries is mediated by increased myoendothelial communication. Am J Physiol Heart Circ Physiol 2020; 319:H123-H132. [PMID: 32469638 DOI: 10.1152/ajpheart.00159.2020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cold exposure causes cutaneous vasoconstriction via a reflex increase in sympathetic activity and a local effect to augment adrenergic constriction. Local cooling also initiates cutaneous dilatation, which may function to restrain cold-induced constriction. However, the underlying mechanisms and physiological role of cold-induced dilatation have not been defined. Experiments were performed to assess the role of endothelial-derived mediators in this response. In isolated pressurized cutaneous mouse tail arteries, cooling (28°C) did not affect the magnitude of dilatation to acetylcholine in preconstricted arteries. However, inhibition of nitric oxide (NO) [NG-nitro-l-arginine methyl ester (l-NAME)] and prostacyclin (PGI2) (indomethacin) reduced acetylcholine-induced dilatation at 37°C but not at 28°C, suggesting that cooling increased NO/PGI2-independent dilatation. This NO/PGI2-independent dilatation was reduced by inhibition of endothelial SK (UCL1684) and IK (TRAM34) Ca2+-activated K+-channels (KCa), consistent with endothelium-derived hyperpolarization (EDH). Cooling also increased dilatation to direct activation of KCa channels (SKA31, CyPPA) but did not affect dilatation to exogenous NO (DEA-NONOate). This cooling-induced increase in EDH-type dilatations was associated with divergent effects on potential downstream EDH mechanisms: cooling reduced dilatation to K+, which mimics an intercellular K+ cloud, but increased direct communication between endothelial and smooth muscle cells (myoendothelial coupling), assessed by cellular transfer of biocytin. Indeed, inhibition of gap junctions (carbenoxolone) abolished the EDH-type component of dilatation to acetylcholine during cooling but did affect NO-dominated dilatation at 37°C. Cooling also inhibited U46619 constriction that was prevented by inhibition of IK and SK KCa channels or inhibition of gap junctions. The results suggest that cooling dilates cutaneous arteries by increasing myoendothelial communication and amplifying EDH-type dilatation.NEW & NOTEWORTHY Cold causes cutaneous vasoconstriction to restrict heat loss. Although cold also initiates cutaneous dilatation, the mechanisms and role of this dilatation have not been clearly defined. This study demonstrates that cooling increases myoendothelial coupling between smooth muscle and endothelial cells in cutaneous arteries, which is associated with increased endothelium-derived hyperpolarization (EDH)-type dilatation. Dysfunction in this process may contribute to excessive cold-induced constriction and tissue injury.
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Affiliation(s)
- Sheila Flavahan
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, Baltimore, Maryland
| | - Nicholas A Flavahan
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, Baltimore, Maryland
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