[Water-salt homeostasis in rats during space flight]

The paper generalized the results of s series of experiments aimed at studying liquid and electrolytes contents in various organs and tissues of rats following 3-week space flights (SF). The results ascertain high reliability of the water-salt homeostasis maintaining system which ensures stable water and electrolytes amounts in the majority of animal tissues in SF. The following alterations appear to be of greatest significance: deduced potassium levels in the heart ventricle tissues in male rats after short-duration (7-9 d) exposure in SF, zero-g-induced degradation of the body ability to bind potassium at injection of isotonic solution KCl into the stomach; redistribution of potassium ions between mother and developing fetuses in space experiments with pregnant animals. Simulated experiments showed that similar shifting of potassium ions in the mother-fetus system may be due not to weightlessness exclusively but other impacts, i.e. they are not specific.