Charge selective properties of the glomerular capillary wall influence antibody binding in rat membranous nephropathy.

IgG antibodies, eluted from kidneys of rats with Heymann nephritis were separated into cationic and anionic fractions, labeled with 125I and 131I, respectively, mixed in equal amounts, and then injected in incremental doses into 10 rats. Glomerular antibody binding was highly correlated with blood concentration of antibody at 24 hr, however, significantly more cationic antibody bound to glomeruli than did anionic antibody at all blood levels studied. The differences were not due to greater antibody content and/or avidity of the cationic preparation, as measured by binding to isolated glomeruli in vitro. These studies demonstrate the influence of glomerular permselectivity and antibody charge on subepithelial antibody deposition.