[The effect of space flight on metabolism: the results of biochemical research in rat experiments on the Kosmos biosatellites].

Cosmos biosatellites research program was the unique possibility to study the metabolic features influenced by space flight factors. Based on the existing ideas about relationships between some metabolic responses, the state of metabolism and the systems of its control in the rats flown in space was evaluated to differentiate the processes occurred in microgravity, possibly under effect of this factor and during first postflight hours. The biochemical results of studying the rats exposed to space environments during 7, 14, 18.5 and 19.5 days and sacrificed 4-11 h after landing (Cosmos-782, -936, -1129, -1667, -2044 flight) are used. The major portion of data are in line with understanding that after landing when the microgravity-adapted rats again return to 1-g environments they display an acute stress reaction. A postflight stress reaction is manifested itself in a specific way as compared to adequate and well studied model of acute and chronic stress and dictates subsequent metabolic changes. Postflight together with the acute stressful and progressing readaptation shifts the metabolic signs of previous adaptation to microgravity are shown up. In the absence of engineering feasibility to control or record the state of metabolism inflight it can only presupposed what metabolic status is typical of the animals in space environments and that its development is triggered by a decreased secretion of the biologically active growth hormone. This concept is confirmed by the postflight data.