An Experimental Study on the Proliferation of Hepatic Ovalocytes

Ductular cell proliferation induced by various chemical carcinogens and its sequences in the experimental animals are well known, . but the significance and fate in relation with cholangiocar cinogenesis through the phase of cholangiofibrosis remain yet inconclusive. The objective of this paper is to clarify the relationship between cholangiofibr• osis and cholangiocarcinoma and the causal role of the former in the cholangiocarcinogenesis. Fifty rats were perorally administered with 0.06 % p-DAB contained regular diet daily by 10 months, and various histologic alterations of intrahepatic biliary system were investigated by light microscopic methods. As a non•specific stage. there were 、". ide range of ovalocytic proliferation during administration of pDAB as a possible role of setting the stage to the carcinoma. With the progression of cholangiofibrosis, was a stage characterized by spotty but noninfiltrative proliferation of those cells with atypical epithelial linings prior to final development of cholangiocar cinoma, equvalent to the stage of dysplasia or precancerous phase; so the term cholangiodysplasia is proposed to indicate dual phase of cholangiofibrosis as a precancerous step to the cholangiocarcinoma During the neoplastic phase were numerical regre ssion of such cholangiodysplastic lesions in accordance to the multicentric development of carcinomatous transformation