[Effect of long space flights on amino acid metabolism].

The amino acid composition of the plasma and serum of Salyut-6 crewmembers who performed flights of different duration was investigated. The parameter was found to vary depending on the flight time and use of different countermeasures. The 75- and 185-day cosmonauts who did not exercise in a full measure showed a decrease in the amino acid pool typical of emergency situations. The 96-, 140- and 175-day crewmembers who exercised as prescribed exhibited the lack of changes in the total content of amino acids and variations in the content of individual amino acids. The results of the study of the amino acid composition can be applied to the evaluation of inflight countermeasures, e.g. exercises, and to the development of rehabilitation measures postflight.