Metabolism of bovine immunoglobulin. I. Metabolism of bovine IgG in cattle with chronic pyogenic infections.

Isolation of IgG-slow by anion exchange chromatography is described. The turnover of IgG-I(131) has been studied in 10 cows, 5 of which were hyperimmunoglobulinemic, i. e. with serum immunoglobulin levels above 3.0gm/100 ml. These hyperimmunoglobulinemias were caused mainly by pyogenic infections. When these cows were compared with 5 normoimmunoglobulinemic cows the salient turnover data were, high fractional turnover rates, short plasma half lives, low Ev:Iv ratios and extended plasma volumes (table I). The results are discussed in relation to similar findings in other animal species and man. Possible mechanisms of the observed hypercatabolism are outlined.