Reticuloendothelial and mesangial function in murine immune complex glomerulonephritis.

The function of the mesangial and reticuloendothelial system was evaluated in normal mice and in mice with nephritis induced by lymphocytic choriomeningitis (LCM) virus infection. Heat-aggregated human immunoglobulin (AlgG) and colloidal carbon served as traceable materials which could be detected in animals' blood and tissues. LCM virus-infected proteinuric (LCM-P) mice, as compared to normal mice or LCM-infected nonproteinuric (LCM) mice, had greater accumulation of AIgG in their glomeruli at all times of examination following i.p. injection of AIgG. The removal rate of AIgG from the kidney, however, was the same in normal and LCM-P mice, indicating an unimpaired mesangial clearing system. This suggested that other mechanisms were responsible for the increased glomerular accumulation of AIgG in LCM-P mice. Reticuloendothelial function was examined directly by i.v. injection of AIgG or colloidal carbon. The data demonstrate that in this model of immune complex glomerulonephritis, colloidal material tested was removed from the blood at a slower rate than it was in normal mice. Deficient clearance of endogenous blood-borne immune complex-like material may be one of the factors playing a role in the accumulation of immune complex-like material in the glomeruli of these nephritic animals.