Objective To inve stigate in vestigate the effects of splenectomy on the expression of the PTEN gene in liver fibrosis of rats induced by biliary tract obstruction.Methods The liver fibrosis model was induced by bile duct ligation.Rats were randomly divided into 3 groups.Group A had bile duct ligation + splenectomy (BDL + SPL,45 rats),group B had bile duct ligation + spleen sham operation (BDL + SSP,45 rats),and group C had sham bile duct ligation + spleen sham operation (SBDL + SSP,45 rats).Liver tissue samples from each group were taken in weeks 1,3,and 5.HE and Sirius staining displayed the degree of liver fibrosis.Western-blot,real-time PCR,and immunohistochemistry SP measured the expression of α-smooth muscle actin (α-SMA) together with the expression of PTEN mRNA and PTEN protein.The relevance was also tested in this study.Results As time increased,liver fibrosis gradually occurred in group A and B,and the degree of liver fibrosis was more serious in group B than in group A.The expression volume of PTEN mRNA and PTEN protein in group A was higher than that in group B (P ＜ 0.05),while the expression volume of α-SMA was the opposite (P ＜ 0.05).The expression volume of PTEN mRNA and PTEN protein were negatively correlated to α-SMA (r =-0.86,P ＜ 0.05).Conclusion In the rat liver fibrosis model,splenectomy up-regulated the expression of the PTEN gene and reduced the secretion of α-SMA,thereby delaying the progression of liver fibrosis.