# 간흡충 감염 햄스터의 담관암발생에서 small cell과 oval cell의 역할

This study was carried out to examine the role of small cells and oval cells in cholangiocarcinogenesis in the hamsters infected with Clonorchis(C) sinensis. Forty two female Syrian golden hamsters were divided into two groups. Group I was for the induction of the cholangiocarcinoma, which was infected orally with C sinensis and given dimethylnitrosamine(15ppm) in drinking water for 4 weeks. Group II was served as control. More than 5 heads of hamsters in each group were sacrificed at 4, 7, 11 and 15 weeks after the beginning of the experiment. The livers were examined histopathologically, electron microscopically and immunohistochemically. The results obtained were as follows; 1. Cholangiocarcinomas were occurred in 1 of 6 animals at 11 weeks and in 4 of 6 animals at 15weeks after the beginning of the experiment. 2. Small cells and oval cells were proliferated around the portal triads from 4 weeks and peaked at 11 weeks, and slightly decreased after then. 3. The strong positive reaction to the $\alpha$-fetoprotein was shown in many of small cells and oval cells. But ductlike oval cells, which were arranged rosette form, showed week positive reaction to the $\alpha$-fetoprotein. 4. Most of small cells and oval cells showed negative reaction to the cytokeratin. But weak positive reaction in ductlike oval cells, and moderate positive reaction in cholangiocarcinoma cells were observed. These results suggested that cholangiocarcinoma induced by infection of C sinensis was believed to originate from the proliferated small cells around the portal triads which would be able to differentiate to the oval cells, ductlike oval cells, and cholangiocarcinoma cells gradually.