[Comparative analysis of weightlessness and hypergravity effects on erythropoiesis in male and female mammals].

The paper summarizes the data obtained in the investigations of bone marrow and blood of Wistar rats exposed to microgravity (Cosmos biosatellites) or 2 G hypergravity (centrifuge). Males, females and pregnant females at various stages of pregnancy have been examined. Under the gravity in the range of +/- 1 G with respect to the earth gravity, in all experiments there were similar changes in erythroid hemopoiesis: a decrease in the total count of blood red cells of bone marrow; a decline in the blood reticulocyte concentrations. There changes in the erythroid part of the rats bone marrow were practically the some in space flights of 7, 14 and 22 days of duration in the centrifuge experiments with animals there alterations were maximal following a 5-day exposure and were absent after one month. Possible reasons of the above changes are discussed stay in 2 G environment.