The Effect Of Erythropoietin And Ischemic Preconditioning On Regeneration Of Remnant Liver With Ischemia Reperfusion Injury

Objective: To investigate the impacts of erythropoietin and ischemicpreconditioning on regeneration and function of remnant liver after70%partialhepatectomy in ischemia reperfusion injury in rats，and to observe the protectiveeffect and mechanism of erythropoietin on the regeneration of the remnant liver.Methods:100male Sprague-Dawley(SD) rats were randomly divided into shamoperation group (SO, n=25), ischemia reperfusion injury group (HIRI, n=25),ischemic preconditioning group (IP, n=25), erythropoietin preconditioning group(EPO, n=25). Specimen was harvested at12hours,24hours,48hours and72hours respectively in four groups. Serum ALT and AST were detected bybiochemery autoanalyzer, liver tissue were stained with liver tissueshematoxylin and eosin (HE) for histologic study, staining of liver wet weight,residual measurement to calculate the regeneration rate of remnant liver tissue,the levels of PCNA, IL-6, Cyclin D1expression were examined in liver tissue byimmunohistochemistry and PT-PCR, comparative analysis of erythropoietin andischemia preconditioning effect on the residual liver regeneration. Results:①Serum ALT, AST levels in EPO and IP groups were lower than that of HIRI group (P <0.05). Compared with IP group, the levels of ALT and AST weresignificantly decreased in EPO group at12hours,24hours,48hours (P <0.05);②Except for the SO group,residual liver cells have different degrees ofdegeneration and necrosis in the rest groups, in which HIRI group washappened necrosis and liver sinus congestion widely at12and24hours, while inEPO group began to mitosis at24hours;③C ompared with the HIRI group, therate of liver regeneration increased significantly in the EPO and IP group at24hours,48hours and72hours(P <0.05). Compared with IP group, its increasedsignificantly in the EPO group at48hours and72hours (P <0.05);④Except forSO group, IL-6and CyclinD1mRNA were expressed in the postoperative24hours to arrive at the peak in the rest groups, which PCNA were expressed at48hours. and the expression of IL-6, CyclinD1and PCNA were decreasedobviously in HIRI group (P <0.05). Compared with IP group, the expression ofIL-6was increased obviously in EPO group at24hours and48hours (P <0.05),the expression of CyclinD1was increased obviously at24hours,48hours and72hours (P <0.05), and the expression of PCNA was increased obviously at48hours,72hours (P <0.05). Conclusion: Erythropoietin and IschemicPreconditioning can effectively reduce hepatic ischemia-reperfusion injury, butthe protective effect of Erythropoietin is better than that of IschemicPreconditioning; Erythropoietin Pretreatment enhances the early expression ofIL-6, cyclinD1, PCNA and promote the division and proliferation of residualliver cell, its better than ischemic preconditioning.