Roles of four liver cells in regulation of PA-plasmin system during liver fibrogenesis in rats

AIM: To investigate the roles of hepatocytes, hepatic stellate cells (HSCs), Kupffer cells (KCs) and endothelial cells (ECs) in the regulation of PA-plasmin system during liver fibrogenesis in rats. METHODS: Experimental liver fibrosis was induced in rats by injection of carbon tetrachloride (CCl₄) twice a week for 12 weeks. Four kinds of liver cells were separated from the normal and fibrotic livers of the rats. The expression levels of urokinase plasminogen activator (uPA), uPA receptor (uPAR) and PA inhibitor-1 (PAI-1) in liver cells were determined by Northern and Western blotting. RESULTS: The expression of PAI-1 and uPAR was markedly increased in HSCs during liver fibrosis in rats as compared to those in the ECs. CONCLUSION: HSCs and ECs may play very important roles in the regulation of PA-plasmin system during liver fibrogenesis in rats. The activated HSCs are main cells to secrete PAI-1 and uPAR.