THE CHANGES IN SERUM PROTEINS AND BLOOD VOLUME DURING IMMUNIZATION

Abstract

In 5 rabbits hyperimmunized with pneumococcal vaccine concentrations of gamma globulin from 3.57 to 10.4 gm % are produced; 4 normal controls have from 0.17 to 0.70%. In these rabbits plasma volume was determined with I131-labelled rabbit albumin and red cell volume with Cr51-labelled autologous red cells. Plasma volume increased with increasing gamma globulin concentration from 28.8 - 32.1 ml/kg in the controls to 72.8 ml/kg in the rabbit with highest gamma globulin concentration. The hemoglobin concentration fell with increasing gamma globulin but the red cell volume was the same in immunized and in normal rabbits. The increase in plasma volume observed is probably due to a regulative mechanism, which attempts to maintain the colloid-osmotic pressure. This regulation mechanism seems to have priority over volume regulation.