Bovine serum albumin nephritis in rats. V. Kinetic studies of antigen localization in various organs and the phagocytic role of polymorphonuclear leukocytes.

Kinetic studies of antigen distribution to various organs were performed throughout the course of experimental immune complex (IC) glomerulonephritis induced in rats. By using a paired radiolabel technique and histologic observations, the authors found massive amounts of antigen within both the lungs and the livers of these rats before the development of glomerulonephritis. However, the rate of antigen disappearance from the lung exceeded that from the liver. Polymorphonuclear leukocytes (PMNs) handled almost all the antigen administered, presumably in the form of ICs. Electron microscopy yielded little evidence that Kupffer cells or monocytes phagocytosed these ICs. After glomerulonephritis developed, only minimal amounts of antigen were evident in the lungs and livers. These observations indicate that the mononuclear phagocyte system (MPS) does not participate in the processing of ICs as previously believed, but that PMNs dispose of nearly all the ICs formed in vivo in this model of glomerulonephritis.