ObjectivesToinvestigatetheeffectofGαq/11signalingpathwayandATP-sensitivepotassiumchannel(KATPchannel)onischemicpreconditioning(IPC)protectioninrathearts.MethodsTwoseriesofexperimentswereperformedinWistarrathearts.Inthefirstseriesofexperiment,ischemicpreconditioningwasinducedbyleftanteriordescendingocclusion(three,5minepisodesseparatedby5minofreperfusion),ischemia-reperfusioninjurywasinducedby30mincoronaryarteryocclusionfollowedby90minreperfusion.Hemodynamics,infarctsizeandscoresofventriculararrhythmiasweremeasured.TheexpressionofGαq/11proteinintheheartwasmeasuredbyWesternblotanalysisinthesecondseries.ResultsIschemicpreconditioningratsshoweddecreasedinfarctsizeandscoresofventriculararrhythmiavsnon-IPcontrolrats.TheeffectofIPCwassignificantlyattenuatedbyglibenclamide(1mg/kg,ip),anonselectiveKATPchannelinhibitor.IPCcausedasignificantincreaseintheexpressionofGαq/11protein.ConclusionsActivationsofGαq/11signalpathwayandKATPchannelplayedsignificantrolesintheclassicalcardioprotectionofischemicprecon-ditioningratheartandmightbeanimportantmechanismofsignaltransductionpathwayduringtheischemicpreconditioning.
