Low p38 MAPK and JNK activation in cultured hepatocytes of DRH rats; a strain highly resistant to hepatocarcinogenesis.

DRH rats are a hepatocarcinogenesis-resistant strain isolated from hepatocarcinogenesis-sensitive Donryu rats, and the liver of DRH shows less histological damage and fewer/smaller neoplastic hepatic lesions by the treatment with hepatocarcinogens. To investigate the mechanism of the resistance, the properties of hepatocytes of DRH and Donryu were compared. In primary culture, DRH hepatocytes exhibited higher proliferation and less apoptosis than Donryu hepatocytes in the presence of EGF and insulin.

Different growth capacity between infant and adult mouse hepatocytes in vitro correlates to the cyclin D1 level without relation to oxidative DNA damage.

Background: Proliferating capacity of hepatocytes is rapidly decreased during growth into maturity, but its exact reason(s) are not well known.

Methods: Hepatocytes isolated from infant (10-14 days old) and adult (10-13 months old) B6C3F1 mice were cultivated in the medium containing epidermal growth factor and insulin. Proliferative capacity, apoptosis, morphological changes, cell cycle proteins and 8-hydroxy-2'-deoxyguanosine (8-OHdG) were compared between the two hepatocyte populations.