Improved Rat Model of Liver Fibrosis induced by CCl_4

Objective To establish a rat model of liver fibrosis,and to improve the classical CCl4 induction method.Methods Forty SD rats(20 female and 20 male) were randomly divided into three groups.Group B(n=14) was given intraperitoneal injection of 2 mL·kg-1of 40% CCl4 solution(a mixture of CCl4 and peanut oil) twice a week and the feeding of normal complete diet.Group A(n=10) was given intraperitoneal injection of 2 mL·kg-1of peanut oil twice a week and the feeding of normal complete diet.Group C(n=16) was given intraperitoneal injection of 5 mL·kg-1of 40% CCl4 solution twice a week and the feeding of diet containing 10% lard and 2% cholesterol.Rats were killed at the end of 8 weeks,and the levels of serum ALT,AST,Alb,TP and A/G were determined by ELISA.The pathological changes in liver tissue were observed by HE and Masson staining.Results Liver function was damaged apparently by CCl4 injection.Some specimens in group B produced false flocculus and achieved the early stage of liver fibrosis,with fatty degeneration in a few liver cells.All specimens in group C had cirrhosis with diffuse hepatic steatosis.The mortality was 28.6% and 43.7% in group B and group C,respectively.Conclusion Liver fibrosis can be induced by injection of low doses of CCl4 and feeding of normal complete diet in rats.In addition,the improved method can reduce the mortality and improve the quality and efficiency of model experiment.