Understanding the interplay of thermal and non-thermal factors on whole-body heat exchange during heat stress

了解热应激期间热因素和非热因素对全身热交换的相互作用

• 批准号: RGPIN-2020-03891
• 负责人: Kenny, Glen
• 金额: $ 4.01万
• 依托单位: University of Ottawa
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=739539
• 关键词: Understanding; interplay; thermal; non; factors

Temperature regulation is a vital aspect of human survival. However, exposure to hot environments (higher ambient temperatures increase the requirements for the body to dissipate heat) and/or heat generated from metabolic processes (increases in metabolic rate augments the heat produced by the body and thus rate that heat must be dissipated) can lead to dangerous increases in body temperature. To offset this increase, highly developed autonomic thermoeffector responses (cutaneous vasodilation and sweating) are activated to facilitate whole-body heat loss during heat stress. However, physiological control of thermoeffector responses and therefore whole-body heat loss can vary as a function of: i) inter-individual (age, sex, other) and intra-individual factors both within (fitness, hydration, other) and beyond (number of exposures, sleep state, other) an individual's control, and ii) the actions of nonthermal factors associated with activation of sensory receptors (baroreceptors, metaboreceptors, osmoreceptors, etc.). Emerging evidence indicates that an interplay between these modulators of heat dissipation may have profound effects on an individual's physiological capacity to dissipate heat. However, our understanding of the interplay between factors remains incomplete. Thus, the main goals of this proposal is to expound the complex interplay of intra-individual factors (fitness, hydration, heat exposure duration) as well as the role of sensory receptor activation associated with baroreceptors, metaboreceptors and osmoreceptors on heat dissipation as a function of inter-individual factors of sex and age. This includes explicating the mechanisms mediating the nonthermal modulation of heat loss responses. These goals will be addressed using an experimental paradigm developed and studied at our research unit which uniquely integrates the use of our one-of-a-kind air calorimeter (device to accurately measure the heat dissipated and stored by the human body) to investigate the control mechanisms governing heat dissipation from a whole-body perspective. Characterizing the physiological interrelations of these factors on the body's physiological capacity to dissipate represents an important step toward advancing our understanding of human heat stress response. By obtaining a comprehensive understanding of the physiological factors affecting a person's ability to live and work in the heat we can generate novel heat protection strategies consisting of monitoring and management solutions and technologies that will provide the maximum level of protection to all Canadians and Canadian workers against the rising threat to human safety - heat. Importantly, the proposed research activities will attract a new cadre of trainees and drive a new generation and culture of scientific growth to address real-world challenges faced by industry and other sectors of our population affected by extreme heat spurred by a warming planet.

温度调节是人类生存的重要方面。然而，暴露于热环境（较高的环境温度增加了身体散热的需求）和/或代谢过程产生的热量（代谢率的增加增加了身体产生的热量，因此增加了热量必须消散的速度）可能导致体温危险升高。为了抵消这种增加，高度发达的自主热效应反应（皮肤血管舒张和出汗）被激活，以促进热应激期间的全身热损失。然而，热效应器响应的生理控制以及因此全身热损失可以作为以下函数而变化：i）个体间（年龄、性别、其他）和个体内因素，（健身、补水、其他）及其他（暴露次数、睡眠状态、其他）个体的控制，以及ii）与感觉受体激活相关的非热因素的作用（压力感受器、代谢感受器、呼吸感受器等）。新出现的证据表明，这些散热调节剂之间的相互作用可能对个人散热的生理能力产生深远影响。然而，我们对各种因素之间的相互作用的理解仍然不完整。因此，本提案的主要目标是阐明个体内因素（健身、水合作用、热暴露持续时间）的复杂相互作用，以及与压力感受器、代谢感受器和热感受器相关的感觉受体激活对散热的作用，作为性别和年龄个体间因素的函数。这包括阐明介导热损失响应的非热调制的机制。这些目标将使用在我们的研究单位开发和研究的实验范式来解决，该研究单位独特地集成了我们独一无二的空气热量计（用于精确测量人体散发和储存的热量的设备）的使用，以研究从全身角度控制散热的控制机制。表征这些因素对人体生理耗散能力的生理相互关系，是推进我们对人类热应激反应的理解的重要一步。通过全面了解影响一个人在高温下生活和工作能力的生理因素，我们可以制定新的热保护策略，包括监测和管理解决方案和技术，为所有加拿大人和加拿大工人提供最大程度的保护，以应对不断上升的人类安全威胁-热。重要的是，拟议的研究活动将吸引新的受训人员队伍，并推动新一代科学发展文化，以解决工业和受地球变暖引发的极端高温影响的其他人口部门所面临的现实挑战。