Biochemical changes in rats flown on board the Cosmos 690 biosatellite

Male rats of the Wistar strain were examined one day and 26 days after the 20-day space flight on board the Cosmos 690 biosatellite. On the 10th flight day the animals were exposed to 24-hour gamma irradiation: some animals were irradiated at a dose of 220 rad and the others at a dose of 800 rad. The data were compared with the results obtained from two control groups one day and 26 days after the experiment: (i) rats kept in the vivarium and fed with a special diet, and (ii) rats from a synchronous experiment (which simulated the flight profile with the exception only of weightlessness). The studies showed the following changes one day after flight: an increase in the concentration of total cholesterol, glucose, urea and corticosterone in the blood plasma, an increase in the concentration of triglycerides in the plasma, liver and bone marrow, a decrease in the concentration of total cholesterol in the adrenals, a reduction in the DNA and RNA content in the spleen and bone marrow, a decline in the potassium concentration together with an increase in the sodium concentration in soleus muscle. The degree and pattern of the changes depended largely on the dose of irradiation. The parameters returned to normal 26 days post-flight.