The Fate of Radioactive Bovine γ-Globulin during the Primary Antibody Response in the Mouse

Abstract

The blood clearance rate and tissue distribution of I¹²⁵ bovine γ-globulin (BGG) in the mouse following a single intraperitoneal injection with and without the stimulus of endotoxin have been studied. The circulatory fate of BGG was found to be similar to that previously described in rabbits. Whole organ counts after initiation of antibody synthesis revealed the greatest levels of radioactivity in the kidneys followed by liver, spleen and lungs. There was a redistribution of residual tissue radioactivity with time such that the relative amount in the kidneys tended to increase and that in the lungs to decrease while the relative amount in the liver and spleen remained essentially constant. Tissue autoradiograms revealed a selective localization of radioactive material in the reactive follicular centers of the spleen and mesenteric lymph nodes as well as the glomeruli of the kidneys. Antibody titers in mice receiving I¹²⁵ BGG alone were higher than anticipated and were equal to those in mice stimulated also with endotoxin. No difference in antigen distribution was seen under these conditions in endotoxin-stimulated mice.