title: Correction of changes in fluid-electrolyte metabolism in manned space flights.
abstract: In order to prevent and correct hypohydration and negative electrolyte balance, the effects of exercises, lower body negative pressure (LBNP) and water-salt supplements (WSS) were investigated in more than 100 test subjects during 14-, 49- and 182-d headdown tilt tests (-4 degrees). A combined use of WSS and LBNP during regular exercises led to a distinct water and sodium retention. These changes were mainly determined by the stimulation of the renin-angiotension-aldosterone and antidiuretic systems. After these countermeasures were tested in simulation studies, they were used by 12 cosmonauts during the 63- and 185-d space flights. The detailed analysis of the postflight examinations of the crewmembers suggests that these countermeasures may exert a beneficial effect on fluid-electrolyte balance.
mesh_terms: D000054:Acceleration; D001510:Bed Rest / Q000009:adverse effects; D001794:Blood Pressure; D006339:Heart Rate; D006728:Hormones / Q000097:blood; D006801:Humans; D007101:Immersion / Q000503:physiopathology; D008150:Lower Body Negative Pressure / Q000379:methods; D005082:Physical Exertion; D011187:Posture; D013026:Space Flight; D013997:Time Factors; D014586:USSR; D014883:Water-Electrolyte Imbalance / Q000378:metabolism / Q000628:therapy*; D014893:Weightlessness
chemical_list: D006728:Hormones