[BASIC PHYSIOLOGICAL MECHANISMS OF HUMAN ADAPTATION TO COLD]

The article provides an overview of the literature that focuses on the main types of human adaptation to cold and mechanisms for increasing heat production. It is shown that the studies in recent years, aimed at studying the molecular mechanisms of adaptation to cold, confirmed the results of previous physiological studies have demonstrated that the major contribution to adaptive thermogenesis during cooling made by oxidative fibers in skeletal muscle (birds, marsupials, large placental and people) and brown adipose tissue (small placenta, especially rodents). The main sources of thermoregulatory heat generation are the contractile activity (thermoregulatory shivering and muscle tone), the uncoupling of oxidative phosphorylation and decrease in thermodynamic efficiency of the ATP-powered pumps (ATPase), which are induced by noradrenaline and thyroid hormones and accompanied by an increase in the consumption of oxygen and energy substrates. During long-term adaptation to cold the number and activity of mitochondria increase to provide enhanced ATP consumption.