Human skeletal muscle thermogenesis and plasticity in response to various environmental conditions

点击翻译按钮获取中文摘要

As endotherms, humans face the vital challenge of maintaining an elevated and constant body temperature under varying environmental conditions, through the metabolic production of heat (thermogenesis). Skeletal muscles are the predominant source of this heat production, however, despite their relative importance for cold survival and performance, the mechanisms that regulate and fuel these heat-producing processes remain poorly understood. The long-term goal of my research program is to elucidate the mechanisms that regulate the heat-producing processes in skeletal muscle of humans exposed to the cold. To accomplish this goal, men and women will be exposed to a single or repeated cold exposure with the aim of understanding: 1) how the stimulation of temperature sensors found in the skin and within internal organs may differentially regulate skeletal muscle thermogenesis during carefully controlled cold exposure in humans; 2) the relative contribution of muscle thermogenesis during acute and chronic cold exposure, the metabolic processes responsible for this muscle thermogenesis and the energy substrates used to fuel them and; 3) whether changes in skeletal muscle metabolism resulting from either repeated cold exposure or exercise training can confer generalized benefits across both types of muscle demands. By combining traditional measurements with novel molecular imaging modalities, the proposed research will build upon the localized view derived from muscle biopsies to non-invasively providing novel and innovative real-time whole muscle-specific metabolism under resting and stimulated conditions. Building a greater depth of understanding in muscle thermogenesis is significant as a means of: 1) improving athletic performance; 2) understanding its impact on locomotion and fine motor movement under various thermal conditions and; 3) understanding the impact of stimulating temperature sensors on the activation of heat-producing metabolic processes. The proposed research also fills the large knowledge gap in the sex-disparities in thermoregulatory and metabolic responses to various environmental conditions. This has dramatic translational implications in the development of biophysical models of human thermal balance. This invariably impacts indoor climate regulations and the energy consumption of commercial and residential buildings, as well as predicting personnel physiological readiness and performance in Canadian Armed Forces and the general labour force.