Abstract
Antiserum from a New Zealand white rabbit raised against the saline soluble fraction of calf bladder epithelium was absorbed to produce epithelial and urothelial specific stages. With indirect immunofluorescence antiepithelial antiserum reacted with all cell layers of the urothelium of a rat, mouse, hamster and guinea pig in all regions of the urinary tract and in the epithelium of the renal pyramid and tubules. The most intense reaction in the urothelium was seen in the superficial cells of the rat and mouse and in the intermediate cells of the guinea pig. Urothelium specific antigens were demonstrated predominantly in the superficial cells of the urothelium as far as the fornix of the renal pelvis but not in the renal pyramids or tubules in all these rodents except for the guinea pig.