Gamma Globulin Metabolism in Rabbits during T H E Anamnestic Response* by Evangelos

A number of diseases in man are associated with markedly increased gamma globulin levels in the serum and an even greater increase in total gamma globulin pool. The most striking of these is multiple myeloma, but elevations are also seen in cirrhosis of the liver, certain of the collagen diseases such as lupus erythematosus and rheumatoid arthritis, and a variety of chronic infectious processes (I-9). Studies of the metabolism of gamma globulin with I131-1abeled human gamma globulin in conditions with an elevated serum gamma globulin level have indicated an increase in the catabolism of gamma globulin (1-4, 8-11). A similar situation appears to exist in animals with increases in gamma globulin levels (12-14), whether due to plasma cell tumors (12), immunization (13), or the passive administration of gamma globulin (14). While these findings indicate that synthesis must increase many fold to achieve the high gamma globulin pool size in the face of an increase in breakdown, none of the studies in man or in tumor-bearing animals have given an accurate picture of the potential capacity of the subject to produce gamma globulin under physiological conditions. Similarly, little is known of the effect of a state which may well approach maximal gamma globulin production, on gamma globulin metabolism. To investigate this problem studies of gamma globulin metabolism have been undertaken in rabbits hyperimmunized with polyvalent pneumococcal antigen, a stimulus known to induce very high levels of gamma globulin (15-18),