Erythrocyte Survival and Blood Volume in the Rat as Determined by Labeling the Red Cells With Cr51

Abstract
Blood was withdrawn from male and from female rats, labeled with Cr51 and introduced intravenously into male and female recipients. Blood volume as determined from dilution of the isotopically labeled cells was found to be 7.47 ± 0.15 of the body weight. The half-life of the labeled cells averaged 8 days, and seemed to be unaffected by growth of the animals.