ObjectiveTo evaluate the therapeutic effect of transplantation of mesenchymal stem cells(MSCs) through the spleen for acute live failure in rat, and to observe migration of transplanted MSCs in vivo. MethodsOne male SD rat was sacrificed to collect MSCs, and MSCs were isolated, expanded, and purified by density gradient centrifugation combined with adhere culture method. The surface antigen expressions of MSCs in the fourth generation were detected by immunohistochemistry method. Twenty-four female rats were given D-galactosamine and tumor necrosis factor α(TNF-α) to establish models of acute liver failure, and then divided into experimental group and blank control group, each group enrolled 12 rats. MSCs of male rat were transplanted into the spleen of female acute liver failure rats in experimental group at 24 hours after model establishment, but rats of blank control group were injected saline(0.5 mL). After the MSCs transplantation, blood samples of rats in 2 groups were got to test levels of serum alanine aminotransferase (ALT), total bilirubin(TBIL), and albumin(ALB). PCR method was used to determine the expression of sex determining region Y gene(SRY gene), and HE staining was used to observe the pathological change of liver tissues of rats in 2 groups. ResultsThe MSCs of the fourth generation expressed CD44 and CD29, but didn't express CD34. There were 5(41.7%) and 3 rats(25.0%) survived at 72 hours, in 1 week and 2 weeks after MSCs transplantation in experimental group and blank control group, respectively, and the survival rate was higher in experimental group(P<0.05). The expression of SRY mRNA was detected in rats of experimental group, as well as the damage of liver tissues in rats of experimental group improved. Compared with blank control group, the levels of ALT and TBIL were lower in experimental group at all time points after MSCs transplantation(P<0.05), but in 1 week and 2 weeks after MSCs transplantation, the levels of ALB in experimental group were higher(P<0.05). ConclusionMSCs can migrate to liver tissue, settle down, and exert the function of replacing hepatocyte after it has been transplanted into the spleen.