[Dynamics of the biochemical makeup of the blood in cosmonauts during flights].

Prolonged space flights (15 to 63 days) led to changes in the biochemical composition of the blood that were observed both during and after flight. Blood samples were withdrawn inflight, stored in a special device onboard and analyzed on return to Earth. The data obtained in real flights were compared with those from the 30-day simulation flight. In real and simulated flights the urea content showed the most significant changes. Inflight it increased to 40 mg% versus 31 mg% preflight. The urea content grew on the 3rd-5th flight day, reaching maximum on the 15-30th day and decreasing again afterwards. The content of glucose and inorganic phosphorus increased slightly whereas that of acid-soluble and lipid phosphorus remained unaltered. The level of cholesterol decreased. The striking similarity between the changes in blood biochemistries during real and simulated flights suggests that they are induced by factors other than weightlessness.