Effect of different concentration of CCl_4 on the establishment of hepatic fibrosis model and the expression of IL-6/TGF-β1 in mice

Objective To explore a reliable method of establishment of hepatic fibrosis model in mice. Methods Forty-six male C57BL/6 mice were randomly devided into control group and model group, and mice in model group were given 15%, 30% or 45% carbon tetrachloride(CCl 4) via intraperitoneal injection for 12 weeks, twice per week; mice in control group were given the same dose of olive oil. Mice were sacrificed 3 d after the injection was finished. The degree of hepatic fibrosis was evaluated. The changes of alanine aminotransferase(ALT), aspartate aminotransferase(AST) and albumin(Alb) were detected with serum biochemistry; protein levels of IL-6 and TGF-β1 in liver tissue were determined by Western blotting. Results There was progressive hepatic fibrosis in model group and liver cirrhosis was appeared in 45% group. In 15%, 30% and 45% group, the mortality and success rate of mice were 8.3%, 16.7%, 41.7% and 27.3%, 80.0%, 57.1%. With the increase of injection concentration, the content of serum ALT and AST were increased gradually(P0.01), but the content of Alb was decreased gradually(P0.01); the expression of IL-6 and TGF-β1 in 45% group were also increased than that of the controls(P0.05). Conclusion Obvious hepatic fibrosis can be induced by the injection of 30% CCl 4 for 12 weeks, and there are higher success rate and lower mortality. It is an ideal method for liver fibrosis model development, which lay a solid foundation for studying the pathogenesis of liver fibrosis.