Histological study on intravesical instillation of Bacillus Calmette Guerin (BCG) and adriamycin for BBN-induced bladder tumor in rats

Abstract

We evaluated histological changes induced by intravesical instillation of Bacillus Calmette Guerin (BCG) and doxorubucin hydorochloride (Adriamycin, ADM) for transitional cell carcinoma of the experimental bladder tumor. We administered rats N-butyl-N (4-hydroxybutyl) nitrosamine (BBN) by mixing it in the drinking water, and performed intravesical instillation of BCG, ADM or physiological saline solution as control in the 16th and 17th weeks and sacrificed in the 18th week after BBN exposure, and observed histological changes by light microscopy and electron microscopy. In the BCG group, the enlargement of the intercellular spaces of superficial tumor cells was found, and electron microscopic findings revealed a decrease or disappearance of the junctional complex. In the ADM group, hydrolytic and vacuolated cytoplasm was revealed. But such change as that in the BCG group was not found in the ADM and control groups. These results indicate that BCG may enlarge the intercellular spaces by changing the junctional complex, and lead to desquamate the tumor cells from the superficial cell layer.