[Culture and characterization of normal human hepatocytes]

Small pieces of normal liver tissues were obtained from patients with gallstones undergoing cholecystectomy, and hepatocytes were isolated from these tissues. They were cultured in a medium of DFH containing several growth factors and hormones, successively for more than two years over 60 passages. They showed doubling time about 25 hours, peak mitotic index near 4% and heteroploid karyotype. They kept secreting some enzymes and albumin, that are usually produced by normal liver tissue. In contrast with hepatoma cells, the cultured normal hepatocytes failed to form xenograft tumor in nude mice and their proliferation was depended upon exogenous growth-factors in vitro. The cultured hepatocytes can be used as a cell model for study of carcinogenic process and stored as a cell-pool for clinical cell transplantation in the coming years.