Objective:To investigate the protective effect of repeated ischemic preconditioning (IP) in a short period on rat liver graft from ischemic reperfusion injury (IRI).Methods: Male Sprague-Dawley rats were used as donors and recipients for orthotopic liver transplantation.The period of cold preservation and anhepatic phase were 120 min and 14 min,respectively.Fifty-four rats were randomly divided into 5 groups.Control group (group A,n=6) received no operation of liver transplantation; liver transplantation group (group B,n=12) received orthotopic liver transplantation by the cuff technique with donor livers perserved for 2 h in 4℃ Ringer’s lactate solution before transplantation; and ischemic precondition group included three subgroups:group C1,C2,and C3(n=12).For group C,the grafts were harvested and then perserved for 2 h in 4℃ Ringer’s lactate solution after ischemic preconditioning,and then used for orthotopic liver transplantation.An IP cycle included 5 min interruption of the portal veins and hepatic arteries of liver,and reflow for 5 min.The C1,C2,and C3 animals were subjected to one,two and three circles,respectively.The activities of AST,ALT and LDH in the sera were examined and the capacity of bile per min was examined 6 hours after operation.The expression of Bcl-2 protein in hepatic tissue was determined with immunohistochemistry.Moreover,the hepatocellular apoptosis were detected by TdT-mediated dUTP-biotin nick end labeling (TUNEL) and the changes of liver ultrastructure were observed under electron microscope.Results: The activities of ALT,AST,and LDH in group B were significantly higher and the capacity of bile per min was significantly lower than those in group A(P<0.01).The activities of ALT,AST,and LDH in group C were significantly higher than those of group A (P<0.01),but were significantly lower than those of group B (P<0.05),and decreased with the increase of IP cycle.Cell morphology examination showed that the changes of graft structure was slighter in group C than in group B,and the expression of Bcl-2 was increased and the apoptotic index was lowered (P<0.01 or P<0.05).Conclusion: Ischemic precondition can relieve IR-induced injury of the donor liver.The protective effect is more potent with repeated IP cycles in a short time.