BackgroundAngiotensinⅡtype1receptor(ATR1)/AngiotensinⅡtype2receptor(ATR2)usuallyinteractwitheachotherintheirexpressionandphysiologicalfunctions,andnitricoxide(NO)isalwaysinvolvedinATR1/ATR2regulationinvivo.Endothelialcellsplayacrucialroleinthemaintenanceofvascularfunctionandinthepreventionofcardiovasculardiseases.ObjectivesToinvestigatetheeffectsofangiotensinⅡ(AngⅡ)andATR1blockervalsartanonATR1,ATR2expressionandtheirrelationwithendothelialnitricoxidesynthase(eNOS)expression,andNOproductioninculturedvascularendothelialcells.MethodsHumanumbilicalveinendothelialcellline(HUVEC)andbovineaorticendothelialcell(BAEC)wereused.BAECwereisolatedfromaortaofnewborncalfbyenzymedigestionandcellsof3-5passageswereused.Cellswereincubatedwithvehicle,AngⅡ,valsartan,orAngⅡplusvalsartanrespectivelyforvariousperiods.ATR1,ATR2,eNOSexpressionandNOproductionweredetected.ResultsIncubationwithAngⅡorvalsartanapparentlydownregulatedATR1mRNAandproteinexpressioninvascularendothelialcells,andthecombinationeffectofthetwodrugsweremoreapparent.AngⅡshowedatransientslightlypromotiveeffectoneNOSandNOgenerationinBAECandanapparentlyinhibitoryeffectwithprolongedincubation,whilevalsartancanapparentlyreversethoseeffects.ConclusionsBothAngⅡandvalsartandownregulatedtheexpressionofATR1invascularendothelialcells.Thesynergisticeffectofthetwodrugswasmoreapparent.ProlongedincubationwithAngⅡcanapparentlyinhibiteNOSexpressionandNOproductioninendothelialcells,whilevalsartancanapparentlyreversethatinhibitoryeffect.
