Liver Epithelial Cell Culture

The establishment of liver epithelial cell lines or strains from newborn or adult rat liver has been reported by many investigators (1 -6 ). The cells of these lines are smaller in size and morphologically more simple than hepatocytes, have a considerable growth potential, and are easy to passage. These features are different from normal rat hepatocytes, which usually do not proliferate without addition of growth factors (7 ), as well as from biliary epithelial cells that quickly proliferate in culture, but cannot simply be subcultured in the absence of factors such as hybridoma growth factor (HGF) (8 ,9 ). The behavior is also different from that of isolated oval cells, which are much more reluctant to proliferate in culture (10 ). Despite this fact, a relationship with oval cells has been claimed (11 ), but is still not proven. Since other nonparenchymal cells do not show an epithelial morphology, it is rather unlikely that such cells could be the origin of these epithelial cells. Thus, the ultimate precursors of these cell lines are still not known, despite many efforts to characterize them using enzyme patterns and other antigens (5 ,6 ,12 ,15 ).