EXPRESSION OF HGF AND TGF-BETA(1) MESSENGER-RNA AFTER PARTIAL-HEPATECTOMY IN RATS WITH LIVER-CIRRHOSIS

Hepatocyte growth factor (HGF) is a potent mitogen for the maturation of hepatocytes in vitro which plays a role in liver regeneration in vi vo, In addition, transforming growth factor-beta(1) (TGF-beta(1)) is a lso a potent regulator of liver regeneration, In attempting to clarify the mechanisms related to liver regeneration after partial hepatectom y, we investigated the expression of HGF and TGF-beta(1) in rats with liver cirrhosis (LC). A rat model of LC was prepared using carbon tetr achloride (CCl4). The expression of HGF mRNA in both the LC and contro l groups showed a similar time-course with the highest expression seen at 18 h after a 70% hepatectomy. The expression of TGF-beta(1) mRNA p eaked at 18 h after partial hepatectomy in the LC group and at 48 h in the control group, The 5-bromo-2'-deoxyuridine (BrdU) labeling index for the LC group at 24, 48, and 72 h after partial hepatectomy was 9.2 %, 5.9%, and 1.8%, while for the control group it was 7.0%, 11.7%, and 6.8%, respectively. The BrdU labeling index in the LC group was thus suppressed earlier than that in the control group. We therefore postul ate that regeneration of the remnant liver in the presence of LC accel erates immediately after partial hepatectomy, but the extent of regene ration is insufficient because of an early cessation due to an early e xpression of TGF-beta(1).