Cell surface coat of human and rat bladder urothelium. I. Ruthenium-red studies in non-neoplastic and neoplastic cells

We have studied the ultrastructure of glycocalyx at the luminal surface of normal and diseased urothelium from humans and rats with ruthenium red staining. A correlation between the thickness and staining intensity of the glycocalyx and the surface topography of the luminal surface was observed. An intensely stained thick glycocalyx was associated with prominent surface microvilli seen in the following conditions in humans: some control urothelium, inverted papilloma, well and moderately differentiated transitional cell carcinomas and mucin producing adenocarcinomas. These changes were also present in rats with FANFT-induced preneoplastic and neoplastic changes. A thin glycocalyx was associated with a scalloped luminal surface containing asymmetric unit membrane plaques and was found in some control human urothelium and in normal rat urothelium. A thin glycocalyx was also associated with the relatively smooth surface seen in poorly differentiated transitional cell carcinomas as well as in some mucin producing adenocarcinomas. We suggest that urothelial glycocalyx, as demonstrated by ruthenium red staining, correlates with the luminal surface topography rather than specific pathological condition of the bladder.