Fluorescence microscopic study on absorption of adriamycin through the rat bladder epithelium

The absorption of adriamycin (ADM) through the rat bladder epithelium was investigated histologically with a fluorescence microscope. ADM permeated through the epithelium into the lamina propria or the inner layer of the muscle within 15 min after instillation, but no further infiltration into the deeper part of the bladder wall was observed thereafter. In addition, fluorescence histological evidence on the uptake of ADM by the endothelial cells of the blood vessels in the lamina propria suggested the systemic diffusion of ADM to the whole body via the circulatory system of the blood. The method reported in the present study is considered to be promising in checking the penetrability of ADM both in the normal bladder wall and bladder tumors.