匹那地尔对大鼠心肌细胞内钙及舒缩功能的影响

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1、匹那地尔对大鼠心肌细胞内钙及舒缩功能的影响作者：林茹,张泽伟,曹春梅,舒强,夏强【摘要】目的探讨匹那地尔对高钾停搏液处理后大鼠离体心肌细胞内游离钙与舒缩功能的影响。方法SD大鼠心室肌细胞酶解分离静息1～2h后随机分为对照组，高钾停搏液组，匹那地尔强化组，格列苯脲拮抗组。四组细胞均在24℃下保存2h,此后对细胞进行复氧、复灌20min并测定细胞收缩、［Ca2+］i瞬态、肌浆网内贮钙释放功能。结果匹那地尔使心肌细胞在缺血再灌注中收缩功能，［Ca2+］i瞬态，肌浆网内贮钙释放能力明显优于高钾停搏液组（P＜0.01〉及细

2、胞内钙释放后的钙峰回落时间明显短于高钾停搏液组（P＜0.01〉。结论匹那地尔通过维持良好的肌浆网和细胞膜Na+/Ca2+交换体功能来调节钙瞬态变化，减少细胞内钙超载从而改善心肌细胞缺血后收缩功能，同时避免了高钾停搏液的负面效应。【关键词】心脏停搏液；心肌细胞；大鼠　　PinacidilImprovesContractileFunctionandIntracellularCa2+inIsolatedRatCardiacMyocytes　　Abstract:OBJECTIVEWeexaminedtheeffectsof

3、pinacidilon12contractilefunctionandintracellularcalciuminisolatedratcardiomyocytesexposedtocardioplegicsolution.METHODSRatmyocyteswereincubatedat24℃for2hoursincardioplegicsolutionwithorwithoutpinacidil(50mmol/L),thentheywereperfusedwithKrebs-Henseleitsolutionw

4、ithagasphaseof95%O2/5%CO2atthesametemperature.Parametersofcontractionandintracellularcalcium［Ca2+］itransientswerethenmeasuredbyvideotrackingandspectrofluorometry.RESULTSDuring20minutesofperfusionafter2hoursincardioplegicsolutionwithpinacidil:(1)therecoveryofco

5、ntractilefunctionswassignificantlyincreasedintermsofbothamplitudeofcontraction(98.30%±9.90%vs81.00%±11.25%,P<0.05)andpeakvelocityofcellshortening(100.90%±13.79%vs76.89%±18.14%,P<0.01)whencomparedwithmyocytesincardioplegicsolutionwithoutpinacidil;(2)theam

6、plitudesofthe［Ca2+］itransientsevokedbyelectricalstimulationandcaffeine(10mmol/L)increasedby23.31%～40.72%and61.73%,respectively,overthoseincardioplegicsolutionwithoutpinacidil;and(3)thedecaytimeofthecaffeine-induced［Ca2+］itransientdecreasedby（36.64±15.10）%relat

7、ivetothatmeasuredincardioplegicsolutionwithoutpinadicil.Theeffectsinducedbysupplementingthe12cardioplegicsolutionwithpinacidilwerediminishedinthepresenceofglibenclamide(10mmol/L).CONCLUSIONAdditionoftheATP-sensitivepotassiumchannelopenerpinacidiltoahighpotassi

8、umcardioplegicsolutionimprovesrecoveryofcontractilefunctionandcytosolicCa2+inisolatedratcardiacmyocytes.　　Keywords：Cardioplegicsloution;Myocyte;Rat　　虽然高钾停搏液能起到较好的心肌保护作用，但仍有证据表明暴露在这