Investigation on the rat liver fibrosis model established by subcutaneous injection of CCl_4

Objective:To study the changes of serological fibrosis parameters and pathological stages of liver fibrosis in rat model injected with CCl4 subcutaneously,and to offer information for clinical empirical studies.Methods:Sixty male SD rats were divided into two groups randomly,8 rats as control group,52 rats as liver fibrosis model group.50% CCl4 was subcutaneously injected twice a week for 12 weeks.At the 3rd,6th,9th,and 12th week,10 rats from liver fibrosis model group and 2 rats from control group were randomly selected to observe the changes of serological parameters and pathological stages of fibrosis.Results:During the development of liver fibrosis,degeneration,necrosis appeared and then fiber septa were formed gradually.The structure of the hepatic lobules was in disorder and finally pseudolobules were formed.After the administration for 3 weeks,4 rats were in S0,5 in S1 and 1 in S2.After the administration for 6 weeks,2 rats were in S0,1 in S1,5 in S2 and 2 rats in S3.1 rat was in S1,3 in S2,4 in S3 and 2 in S4 when injected for 9 weeks.1 rat was in S2,2 in S3 and 7 in S4 after 12 weeks administration.The serum level of HA,PCⅢ,C-Ⅳ and LN increased with the severity of liver fibrosis.Serum HA and LN levels were higher in S3 and S4 stage than those in S1 and S2 stage in control group(P0.05).The levels of PCⅢ and C-Ⅳ were higher in S4 stage than those in S1,S2 and S3 stage in control group(P0.01).Conclusions:Different degrees of hepatic fibrosis in rats can be successfully established by injecting CCl4 subcutaneously,which is an ideal approach to the establishment of liver fibrosis model and should be widely used in clinical and empirical studies.