Measurement of the Antibody Response by the Elimination of I131-Labeled Proteins. I. The Elimination of I131-Labeled Proteins from the Blood of Normal Mice

摘要

The effect of a number of variables on the elimination of I131-labeled proteins from the blood of normal mice was studied. The purpose of these studies was to arrive at a critical evaluation of the antigen elimination technique which will be used for the measurement of the immune response in studies on the recovery from radiation injury. The method is based on the fact that the biological half-life of a protein is reduced in the presence of specific antibodies in the blood. It was found that the elimination of I131-horse serum albumin in normal LAFl mice - under the experimental conditions employed - was not affected by the amount of protein injected or by the time of sampling. Although the degree of labeling had no effect on the half-life measured, a shift of the elimination curve was observed which was time dependent. This change was attributed to radiation damage of the protein by the radioactive label. The elimination characteristics of a number of different proteins for possible use in the immunization experiments was studied. Considerable differences were observed in the way closely related proteins were eliminated from the blood. The half-life of the albumins ranged from 13.36 hours for I131-porcine serum albumin to 22.03 hours for I131-dog serum albumin. (Author)