[Hormonal regulation of metabolism in the human body in microgravity and during simulation of its physiological effects].
The paper presents results of investigations into the effects of space flight and simulation experiments of various length on the hormonal regulation of metabolism in the human body. Microgravity was shown to instigate shifts on different levels of the hormonal regulation and consequent adjustment of metabolism to this new environment. For instance, adaptation occurs on the level of basal secretory activity resulting in altered metabolism and formation of a pool of hormones. Metabolism readaptation to the Earth's gravity is dependent on polymorphic processes in the system of hormonal regulation developing in the course of time. Trends in the hormonal regulation of water-electrolyte metabolism during early adaptation point to inequality of contributions of the antidiuretic hormone, natriuretic peptide, and the renin-angiotensin-aldosterone system. In the ground-based simulations responses of the hormonal regulation of water-electrolyte metabolism differ in intensity and types of hormones involved. Temperature variation can modify reactions of the comosis and volume regulating hormones at the beginning of adaptation. Physical-chemical regulation of calcium homeostasis in microgravity reveals itself by a rapid decline of the calcium-binding ability of blood buffers and, later on, degradation of the relative ability of extraplasmic structures to bind calcium. Qualitative and quantitative changes in the diurnal rhythm of the suprarenal steroidogenesis are indicative of modification of intensity of reactions of the main biosynthetic sequences. Countermeasures used by test-subjects in these investigations loosened significantly the aldosterone-secreting biosynthetic sequences but were favorable to the synthesis of testosterone and hydrocortisone. Some of the highly variable processes of hormonal regulation were mute to the diurnal rhythms in the pre-flight and preexperimental periods.
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D000222:Adaptation, Physiological / Q000502:physiology; D002021:Buffers; D002118:Calcium / Q000097:blood / Q000378:metabolism*; D002940:Circadian Rhythm / Q000502:physiology; D013007:Growth Hormone-Releasing Hormone / Q000378:metabolism; D006706:Homeostasis / Q000502:physiology; D006801:Humans; D006854:Hydrocortisone / Q000378:metabolism; D045283:Natriuretic Agents / Q000378:metabolism*; D009995:Osmosis / Q000502:physiology; D012084:Renin-Angiotensin System / Q000502:physiology*; D013026:Space Flight; D013696:Temperature; D014667:Vasopressins / Q000378:metabolism*; D014893:Weightlessness
D002021:Buffers; D045283:Natriuretic Agents; D014667:Vasopressins; D013007:Growth Hormone-Releasing Hormone; D002118:Calcium; D006854:Hydrocortisone