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1、匹那地爾對大鼠心肌細胞內鈣及舒縮功能的影響作者:林茹,張澤偉,曹春梅,舒強,夏強【摘要】目的探討匹那地爾對高鉀停搏液處理后大鼠離體心肌細胞內游離鈣與舒縮功能的影響。方法SD大鼠心室肌細胞酶解分離靜息1~2h后隨機分為對照組,高鉀停搏液組,匹那地爾強化組,格列苯脲拮抗組。四組細胞均在24℃下保存2h,此后對細胞進行復氧、復灌20min并測定細胞收縮、[Ca2+]i瞬態(tài)、肌漿網內貯鈣釋放功能。結果匹那地爾使心肌細胞在缺血再灌注中收縮功能,[Ca2+]i瞬態(tài),肌漿網內貯鈣釋放能力明顯優(yōu)于高鉀停搏液組(P<0.01〉及細
2、胞內鈣釋放后的鈣峰回落時間明顯短于高鉀停搏液組(P<0.01〉。結論匹那地爾通過維持良好的肌漿網和細胞膜Na+/Ca2+交換體功能來調節(jié)鈣瞬態(tài)變化,減少細胞內鈣超載從而改善心肌細胞缺血后收縮功能,同時避免了高鉀停搏液的負面效應。【關鍵詞】心臟停搏液;心肌細胞;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 雖然高鉀停搏液能起到較好的心肌保護作用,但仍有證據(jù)表明暴露在這