DISTRIBUTION OF HETEROLOGOUS ANTI-PEROXIDASE ANTIBODIES AND THEIR FRAGMENTS IN SUPERFICIAL RENAL CORTEX OF NORMAL WISTAR-MUNICH RAT - ULTRASTRUCTURAL-STUDY

Abstract

The distribution of serum proteins in the superficial renal cortex of normal Wistar-Munich rats was studied using a new technique. Heterologous antiperoxidase antibodies (160,000 daltons), their antigen-binding fragments F(ab'')2 (100,000 daltons), and Fab (50,000 daltons) were injected i.v. and then demonstrated by incubation with free peroxidase after in situ fixation. This technique offered several advantages including each and uniform detection of the proteins, even in tubular cells, and a high degree of specificity and accuracy. The glomerular filtration barrier was found to be complete for Ig[immunoglobulin]G and incomplete for F(ab'')2 and Fab fragments. This barrier for IgG was localized in the lamina densa. The filtered proteins were found to be reabsorbed and degraded in the proximal tubule. The 3 proteins were diffusely detected in the interstitial tissue and in tubular intercellular spaces up to the apical tight junctions.