On the fate of proliferated oval cells in the early stage of 3'-Me-DAB-induced hepatocarcinogenesis

The proliferation of the so-called oval cells is quite interesting for elucidating azo-dyeinduced hepatocarcinogenesis. The purpoSe of this study is to investigate the fate of proliferated oval cells in the early stage of 3'-Me-DAB-induced hepatocarcinogenesis by light microscopic, electron microscopic and autoradiographic method. Ultrastructurally, the cells possessing characteristics intermediate between oval cells and small basophilic hepatocytes were frequently observed. Furthemore, it was concluded that some oval cells were able to transform into hepatocytes autoradiographically. Therefore, it was suggested that some oval cells were transformed into small basophilic hepatocytes and further differentiated into mature hepatocytes. Meanwhile, other oval cells take part in the formation of cholangiofibrosis. After all, oval cells play the leading part in the course of 3'-Me-DAB-induced hepatocarclnogenesis.