抄録
The effects of exogenous growth hormone (GH)-treatment on the development and regeneration of CCl4-induced acute hepatic injury were examined in GH-deficient Mini rats. Alanin aminotransferase (ALT) and asparate aminotransferase (AST) activities increased significantly at 24 and 48 hours (h) after CCl4-administration in both GH-treated and non treated groups, and they tended to be suppressed by GH-treatment. The expression level of insulin-like growth factor (IGF)-1 mRNA was higher in GH (+) CCl4 (+) group than in GH (-) CCl4 (+) group, especially at 72 h, and that of hepatocyte growth factor (HGF) mRNA was also higher in some points in the former group. Histologically, degenerative changes of hepatocytes observed at 24 and 48 h was less severe in GH (+) CCl4 (+) group than in GH (-) CCl4 (+) group. At 72 h, depositions of reticular fibers and extracellular matrix materials were less severe and the number of desmin- or α-SMA-positive cells was larger in GH (-) CCl4 (+) group than in GH (+) CCl4 (+) group. Proliferating cell nuclear antigen (PCNA)-labeling index of centrilobular hepatocytes increased at 48 h in both GH (+) CCl4 (+) and GH (-) CCl4 (+) groups, and it returned to the control level at 72 h in the former group while that in the latter group showed still higher level at 72 h. In this study, it was shown that CCl4-induced acute liver injury in Mini rats can be restored by exogenous GH-treatment, and upregulation of IGF-1 and HGF mRNAs may be involved in this phenomenon.
