Primary culture of adult rat liver cells. II. Cytological and biochemical properties of primary cultured cells.

Primary mass culture of isolated cells from adult rat livers by the trypsin-perfusion method uas carried out to investigate cytological and biochemical properties of primary cultured cells. Two main types of cells were found in the course of primary culture of isolated hepatic cells. One was a group of polygonal cells with granular cytoplasm, which appeared to arrange themselves in cords and clusters 3 to 4 days postinoculation and then gradually decreased in number. These cells seemed to be associated with expression of liver specific functions such as higher tyrosine aminotransferase levels and transient increases in albumin production. Another type of cells was relatively small in size and had clear cytoplasm, which grew out rapidly in place of the polygonal cells and proliferated also in subculture. alpha-Fetoprotein was detected in the cultured media of the proliferating clear cells. These results suggest that the polygonal cells and the clear cells may correspond to the mature hepatocytes and the hepatocytic stem cells in vivo, respectively.