Studies on hepatocyte apoptosis,proliferation and oncogene c-fos expression in carbon tetrachloride-induced cirrhotic rat liver

Summary  To investigate the significance of hepatocyte apoptosis, proliferation and oncogene c-fos expression in carbon tetrachloride (CCl₄)-induced cirrhotic rat liver. Rat cirrhosis was induced by subcutaneous injection of 50% (v:v 1:1) CCl₄. Hepatocyte apoptosis, proliferation and oncogene c-fos expression were examined with TUNEL, PCNA and c-fos immunohistochemical methods in control group and treatment group 72 h, 5, 7, 11 and 15 weeks after CCl₄, induction. Hepatocyte apoptosis was rarely seen in control rat liver. The hepatoeyte apoptosis was obviously increased 72 h after treatment. Fifteen weeks after treatment, the apoptosis was still more obvious in treatment group than that in controls. PCNA was constantly expressed in CCl₄ group, with highest level at middle phase. C-fos was positive 7 and 11 weeks after CCl₄ treatment. The results suggest that: 1) apoptosis is involved in rat liver damage at the early phase in CCl₄-induced injury, and the process can alleviate nodule reconstruction or eradicate potentially mutational hepatocytes at the later phase; 2) hepatocytes constantly proliferate in CCl₄-induced rat liver cirrhosis, especially at the middle phase; 3) c-fos might modulate hepatocyte proliferation in CCl₄-induced rat liver cirrhosis.