Comparison of reactions of antibodies to rat collagen and to rat kidney in the basement membranes of rat renal glomeruli.

By in vivo and in vitro methods of immunofluorescence, antibody to rat collagen and to rat kidney show the same regular, linear fluorescence following the outlines of the renal glomerular capillaries. Absorption of each antiserum with its homologous antigen completely removed the antibody for immunofluorescence, while absorption with the heterologous antigen had no effect. The nephrotoxicity persisted in the anti-kidney serum absorbed with collagen. By pretreatment of frozen normal rat kidney sections with various enzymes followed by immunofluorescence, it was shown that trypsin and hyaluronidase had no effect on the subsequent fluorescence of either antibody; papain reduced the fluorescence; and pepsin and Pronase acted on both antigens so that no fluorescence was present. One preparation of neuraminidase, derived from V. cholerae, reduced fluorescence of both antibodies in some preparations, but the same enzyme derived from influenza virus or C. perfringens had no effect on either. Collagenase completely prevented fluorescence of the antibody to collagen and had no effect on that to rat kidney. The findings in this study show that the antibody to collagen is directed to collagen in rat renal glomerular basement membranes and that the antibody to rat kidney reacts with some antigen other than collagen in these membranes.