Protein permeability and immune complex deposition in glomerular capillary walls of rats

The effect of reduced glomerular anionic charge on immune complex deposition in the glomerular basement membrane was studied in rats with Heymann nephritis. A reduction of the anionic charge was induced by lysozyme administration. The animals were divided into the following four groups: normal controls (group A), group B treated with lysozyme, group C treated with lysozyme and immunized with autologous tubular antigen, and group D immunized with the antigen. Proteinuria was marked in groups B, C and D as compared with group A, especially in group D. Development of Heymann nephritis by the tubular antigen was suppressed in group C. Stainings of anionic substances in the glomerular capillary walls by cationic probes were weakened in groups B, C and D. Immune complex deposited in the subepithelial area of the capillary wall was also stained by cationic probes. The findings suggest that reduced glomerular anionic charge by polycations results in suppressed immune complex deposition in the basement membrane, partially due to increased permeation of macromolecules across the glomerular capillary walls in rats.