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: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=757178
• 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。但是，暴露于热环境（更高的环境温度增加了人体散发热量的要求）和/或由代谢过程产生的热量（代谢率的增加增加了人体产生的热量，因此必须散发热量的速度）可以导致体温升高。为了抵消这种增加，高度发达的自主神热反应（皮肤血管舒张和出汗）被激活，以促进热应激期间的全身热量损失。但是，热弹药反应的生理控制，因此全身热量损失可能会因：i）个体间（年龄，性别，其他）和个体内部因素（适应性，水平，其他）及以后（暴露量，睡眠状态，其他）控制和ii）与激活感官受体（压力感受器，分泌物受体，释放感受器等）相关的非热因素的作用。新兴的证据表明，这些散热调节因子之间的相互作用可能会对个人的生理能力产生深远的影响。但是，我们对因素之间相互作用的理解仍然不完整。因此，该提案的主要目标是阐述个体内因素（适应性，水合，热暴露持续时间）的复杂相互作用，以及与压力感受器，变质受体和受体受体相关的感觉受体激活的作用性别与年龄的个体间因素。这包括解释介导热量损失反应的非热调节的机制。这些目标将使用在我们的研究部门开发和研究的实验范式来解决，该范式唯一整合了我们一种独一无二的空气热量计（以准确测量人体耗散和存储的热量的设备）来研究从全身的角度来控制散热的控制机制。表征这些因素在人体散射的生理能力上的生理相互关系是促进我们对人类热应激反应理解的重要一步。通过了解影响一个人在热量中生活和工作能力的生理因素的全面理解，我们可以生成新型的热保护策略，包括监测和管理解决方案和技术，这些策略将为所有加拿大人和加拿大人提供最大的保护水平对人类安全的威胁不断上升​​ - 热量。重要的是，拟议的研究活动将吸引新的学员干部，并推动新一代和科学成长的文化，以应对行业和其他人口的其他部门面临的现实世界挑战，受到温暖星球刺激的极端热量影响。