简介：ThepresentstudywasdesignedtodeterminetheeffectsofGuanfubaseA(GFA)onthelatesodiumcurrent(INa.L),transientsodiumcurrent(INa.T),HERGcurrent(IHERG),andKv1.5current(IKv1.5).ThevaluesofINa.L,INa.T,IHERGandIKv1.5wererecordedusingthewhole-cellpatchclamptechnique.Comparedwithotherchannels,GFAshowedselectiveblockingactivityinlatesodiumchannel.ItinhibitedINa.Linaconcentration-dependentmannerwithanIC50of(1.57±0.14)μmol·L-1,whichwassignificantlylowerthanitsIC50valuesof(21.17±4.51)μmol·L-1fortheINa.T.TheinhibitoryeffectofGFAonINa,Lwasnotaffectedby200μmol·L-1H2O2.ItinhibitedIHERGwithanIC50of(273±34)μmol·L-1andhasslightblockingeffectonIKv1.5,decreasingIKv1.5byonly20.6%at200μmol·L-1.Insummary,GFAinhibitedINa.Lselectivelyandremainedsimilarinhibitioninpresenceofreactiveoxygenspecies..ThesefindingsmaysuggestanovelmolecularmechanismforthepotentialclinicalapplicationofGFAinthetreatmentofcardiovasculardisorders.