The rat renal papillary interstitium which contains abundant proteoglycans is a unique area
important in renal function. These proteoglycans were studied ultrastructurally by ruthenium
red fixation and staining and phosphate-buffered fixation before and after enzyme digestion.
A tissue culture of rat renomedullary interstitial cells, the predominant cell of the renal
papillary interstitium, was studied for its ability to synthesize proteoglycans and the
proteoglycans were then analyzed. Tissue slices of whole rat renal inner medulla were also …