简介：ObjectiveToinvestigatethealterationsofL-typecalciumcurrent(IcaL)inabdominalaorticligation-inducedhypertrophiedratheartsandtheeffectoflosartanonthesealterations.METHODSCardiachypertrophywasinducedbyabdominalaorticligationinrats.TorecordIcaL,whole-cellpatch-clamptechniquewasused.RESULTSMembranecapacitancewaslargerinhypertrophiedcells(148±29pF)thaninsham-operatedcells(102±14pF,P<0.01)andlosartan-treatedcells(118±27,P<0.01).ThemaximalpeakIcaLWasincreasedfrom-835±124pAinsham-operatedcellsto-1404+_417pAinhypertrophiedcells(P<0.01),thecorrespondingIcaLdensitywasincreasedfrom-7.5±1.8pA.pF^1to-10.5±2.2pA.pF^1(P<0.01),whiletheywerereducedto-956-2:170pF(P<0.01)and-8.2±1.6pA.pF^1(P<0.05)respectivelyinlosartan-treatedcells.Themembranepotentialofhalfmaximalactivationofthehypertrophiedcells(-20.6±1.0mV)shiftedtomorenegativepotentialsthansham-operatedcells(-15.6±1.6mV,P<0.01)andlorsartan-treatedcells(-17.4±1.0mV,P<0.01).Theslopeoftheactivationcurveofhypertrophiedcells(5.7±0.4)wasdecreasedslightlythansham-operatedcells(6.4±0.5,P<0.05).Themembranepotentialofhalfmaximalinactivationofhypertrophiedcells(-27.6±1.9mV)shiftedtomorepositivepotentialsthansham-operatedcells(-31.4±2.2mV,P<0.05).Theslopeofinactivationcurveswerenotdifferentinthethreegroups.