简介：Objective:Tostudytheprotectiveeffectofischemicpreconditioning(Ⅰ-pre)andischemicpostconditioning(Ⅰ-post)againstischemia/reperfusion(I/R)injuryinrat'sliver.Methods:UsingratmodelofhepaticsegmentalI/Rinjury,ratsweredividedinto5groups:GroupA(shamgroup),GroupB(I/Rinjury),GroupC(Ⅰ-pregroup),GroupD(Ⅰ-postgroup)andGroupE(combinedtreatmentofⅠ-preandⅠ-post).Serumalanineaminotransferase(ALT),aspartateaminotransferase(AST),malondiaidehyde(MDA),glutathione(GSH),superoxidedismutase(SOD),glutathioneperoxidase(GSH-Px)andmyeloperoxidase(MPO)inhepatictissuesweredetermined,respectively.Inaddition,7days'survivalofGroupsB,C,DandEwereevaluated.Results:ComparedwithGroupB,GroupsC,DandEexhibitedsignificantlydecreasedALTandASTrelease,minimizedtissueinjury,suppressedvaluesofMDAandMPO,increasedactivitiesofSOD,GSH-PxandGSH(P<0.05),aswellasimprovedanimalsurvival.ThedifferencesamongGroupsC,DandEwerenotstatisticallysignificant.Conclusions:Ⅰ-pre,Ⅰ-postandcombinedtherapyofⅠ-preandⅠ-posthaveprotectiveeffectagainsthepaticI/Rinjury,whichiscorrelatedwithitsfunctionofreducingtheproductionofreactiveoxygenspecies,maintainingtheactivitiesofantioxidantsystemsandsuppressingneutrophilsrecruitment.NoadditiveeffectcanbeobtainedinGroupE.