Effect of Total Body X-Irradiation on Plasma Volume, Red Cell Volume, Blood Volume and Thiocyanate Space in Normal and Splenectomized Rats

¹ From the Department of Pharmacology and Institute for Medical Research, University of Louisville School of Medicine, Louisville, Kentucky

A single dose of 600 r of x-ray was given to groups of nonanesthetized normal and splenectomized rats. Simultaneous estimations of plasma volume, red cell volume, and thiocyanate space were performed in these animals before and after x-irradiation. In normal rats plasma volume decreased in the first 8 days postirradiation but showed a significant increase by the 10th day. The reduction of red cell volume and hematocrit developed gradually and was markedly shown by the 10th day. The blood volume after irradiation was generally larger than that of the normal value. The SCN space increased on the 4th day after irradiation then decreased in the next period and was elevated again by the 10th day postirradiation. In splenectomized rats the change of SCN space was similar to that observed in normal rats and the changes of blood volume were varied. A marked reduction of red cell volume with an increase, probably compensatory, of plasma volume, developed in these rats by the 4th day after x-irradiation.