A COMPARATIVE-STUDY OF THE DESQUAMATION OF UROTHELIAL CELLS DURING GESTATION AND IN ADULT MICE FOLLOWING MODERATE STRESS OR ENDOTOXIN TREATMENT

The present paper deals with the comparative EM study of the detachmen t of mouse urinary bladder epithelial cells under various physiologica l conditions, namely, during gestation and in adult mice following ind uction by endotoxin or by exposure to moderate stress. It has been sho wn that desquamation during gestation involves two district modes, she dding of single cells and formation of apopiotic bodies. Moderate stre ss in adult female mice induced by constant illumination for 72 or 96 hours, results in desquamation of superficial and intermediate cells. Application of LPS is followed by desquamation of single cells and who le sheets of cells. Cell detachment involves interruption of tight jun ctions between neighbouring cells and formation of numerous cup shaped vesicles, multivesicular bodies and vacuoles at the base of desquamat ing cells. LPS induces desquamation entails delivery of lysosomal enzy mes extracellulary into the intercellular space. In the areas of sloug hing the bladder epithelium lack permeability barrier. Desquamated cel ls in the bladder lumen are mostly alive. These results clearly demons trate the existence of specific adhesion mechanisms of detachment and desquamation of uroepithelial cells.