CHARACTERIZATION AND DISTRIBUTION OF INTERSTITIAL CELL-TYPES IN THE RENAL-CORTEX OF RATS

A precise classification of the cellular components of the cortical pe ritubular interstitium is missing in spite of its physiological and pa thophysiological importance. By combining electronmicroscopy and immun ohistochemistry we attempted to better identify and localize the diffe rent interstitial cell types in rat kidney, with special attention to the cortex. Antibodies against common leukocyte antigen (OX1), a macro phage antigen (ED 2), MHC class II antigen (OX6) and ecto-5'-nucleotid ase were applied to cryostat sections, The two latter antibodies were used additionally in electron microscopy. Four groups of cell types we re identified that displayed distinct antigenic patterns, distribution s and morphological features. They were identified as fibroblasts, den dritic cells, macrophages and lymphocytes. Fibroblasts and dendritic c ells constituted the most abundant cell types in the cortex and outer medulla, and they were rather uniformly distributed in these zones thr oughout the peritubular interstitium, where macrophages were very scar ce. The latter were abundant in the connective tissue of large vessels and of the pelvic wall. The incidence of lymphocytes was generally lo w. These data may be helpful on the one hand for the further phenotypi c characterization of renal interstitial cells and on the other hand f or the evaluation of the roles of those cells in pathological processe s.