[The role of individual reaction s of thermal and water-electrolyte metabolism to suited immersion].
Role of individual reactions of thermal and water-electrolyte metabolism and their relation to the mechanisms of hormonal control were studied during suited immersion (SI). The investigation consisted of 177 man/exposures from 3 hrs up to 3 days of 46 male volunteers. Parameters of mass, heat and water-electrolyte metabolism, and hormonal control were determined on a background of monitoring consumption of special ratios. Based on the complex evaluation of tolerance of weight-free SI for 1 to 3 days, parameters of thermal and hydroionic homeostasis were found to be the predictor variables. Extreme types of reactions to SI were in the ratio of 1:4 (tolerant/intolerant subjects). An extreme reaction appears to be an individual constitutional characteristic of the body the dimensions of which are equal during repeated immersion. As for the water-electrolyte parameters, extreme levels of SI tolerance were significantly different in the amount and velocity of renal excretion of liquids and liquid losses due to perspiration (897 +/- 253 ml and 2010 +/- 218 ml in SI tolerant and intolerant subjects, serotonin variability in everyday life and serotonin dynamics during SI (significant increase in tolerant subjects and no dynamics in intolerant subjects after 24 hrs in SI). The complex evaluation of the reaction showed nonstationary thermal state and reduction of oral temperature by 1 degree C in SI intolerant subjects after initial 1-1.5 days of exposure. In the course of 3 days, the negative water balance showed an increase; body mass losses were in parallel with the development of motion sickness and hyperventilation, and disturbance in the rhythm of the sympathoadrenal activity. The renin-aldosterone system reacted most actively out of all the hormonal systems and did not adapt to SI within a day and a half. Thermal state of SI tolerant subjects was stationary during 1-1.5-d immersion; oral temperature dropped by 0.2-0.4 degree C, liquid losses and AP deviations were relatively small and blood osmolality remained unchanged on a background of stable adaptive reactions of various components of the neuroendocrine system. Adaptation to SI occurred in the period from one day to a day and a half.
Larina
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Lakota
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D000222:Adaptation, Physiological / Q000502:physiology; D000324:Adrenocorticotropic Hormone / Q000378:metabolism; D000450:Aldosterone / Q000378:metabolism; D015992:Body Mass Index; D001833:Body Temperature Regulation / Q000502:physiology*; D005676:Gravity Suits; D006728:Hormones / Q000378:metabolism*; D006801:Humans; D006854:Hydrocortisone / Q000378:metabolism; D007328:Insulin / Q000378:metabolism; D008297:Male; D009041:Motion Sickness / Q000378:metabolism; D012083:Renin / Q000378:metabolism; D012701:Serotonin / Q000378:metabolism; D019442:Space Suits; D013997:Time Factors; D014882:Water-Electrolyte Balance / Q000502:physiology*
D006728:Hormones; D007328:Insulin; D012701:Serotonin; D000450:Aldosterone; D000324:Adrenocorticotropic Hormone; D012083:Renin; D006854:Hydrocortisone