Studies on the erythron and the ferrokinetic responses in beagles adapted to hypergravity

Red cell survival, ferrokinetics, and hematologic parameters were investigated in Beagle dogs exposed to chronic hypergravity (2.6 Gx). Ineffective erythropoiesis, red cell mass, plasma volume, and 51 Cr elution were significantly increased; maximum 59Fe incorporation was decreased; and there was no change in the mean erythrocyte life span following autologous injection of 51Cr-labeled red cells and 59Fe-labeled transferrin. Red cell count, Fcells, total body hemoglobin (Hb), susceptability to osmotic lysis, and differential reticulocyte count were increased. White blood cell count, venous blood %Hb, mean cell volume, mean cell Hb, mean cell Hb concentration, and serum iron were decreased. No changes were observed for body mass, mg Fe per g Hb, iron binding capacity, percent saturation of iron carrying capacity, or the electrophoretic mobility of purified Hb. This study indicated that chronic exposure to hypergravity induced changes in red cell size, volume, total mass, and membrane permeability.