Objective:Toobserveeffectsofarginineonarterialendotheliuminjuredbyischemia-reperfusion(IR),andexploreitspossiblemechanism.Methods:Fifty-fourratswerepidedinto3groupsandtreatedinrespectiveways:(1)drinkingtapwaterasthecontrol;(2)drinkingtapwatercontaining2.5%L-arginine;(3)drinkingtapwatercontaining2.5L-argininetogetherwithintraperitonealinjectionofN^G-nitro-L-argininemethylester5mg·kg^-1·d^-1.asegmentofthecommoncarotidarterywasoccludedfor1h,andthenreperfused.Samplestakenatdifferentpost-IRtimefromthesegmentwerepreparedfortheultrastructuralandCeH2O2cytochemicalobservation.Thenakedindex(NI)ofinternalelasticlamina(IEL)wasmeasuredforcomparingtheendothelialinjureextentanditsrepairprocess.Results:Lessdamageofendothelialcells(EC),moreplateletsadheringtonakedIELandmoreregeneratingECwereobservedinGroup2.TheNIvaluesofsamplestakenat1,2,3daftertheIRwererespectively0.92±0.08,0.88±0.03and0.41±0.02inGroup1,andreducedto0.52±0.05,0.19±0.08and0.06±0.01inGroup2(P<0.05-0.01).InGroup3,theendotheliumdamagewasnotalleviated,andsoweretheNI.TheCe-H2O2particlesdepositedonthelumensurfaceofendotheliumweremuchlessinGroup2thaninGroups1and3.Conclusions:L-argininepromotestherepairprocessofIR-injuredendotheliumprobablythroughtheremovalofoxygenfreeradicalsbyNO.
