大鼠心房肌细胞延迟整流钾通道电流特性及伊布利特对其影响  

Patch clamp study of ultra-rapid delayed rectifier-potassium channel and the effect of Ibulitide on rat isolated atrial myocytes

作　　者：李琼[1] 李健[2] 吴冬燕[1] 任静[1] 卢凤民[1] 许静[1] LI Qiong;LI Jian;WU Dong-yan;REN Jing;LU Feng-min;XU Jing(Tianjin Chest Hospital, Tianjin 300222, China;Tianjin Medicine University Second Hospital)

机构地区：[1]天津市胸科医院,300222 [2]天津医科大学第二医院

出　　处：《天津医药》2017年第2期168-171,共4页Tianjin Medical Journal

摘　　要：目的通过膜片钳技术研究大鼠心房肌细胞延迟整流钾通道(IKur)的电流特性,以及伊布利特对大鼠心房肌细胞IKur的影响。方法大鼠离体心脏行主动脉插管,应用Langendorff装置恒流灌流,依次用无钙台氏液、Ⅱ型胶原酶,分离出大鼠单个心房肌细胞,采用标准的全细胞膜片钳技术记录IKur的电流图,计算电压电流曲线(I-V曲线),采用伊布利特配成2μg/L溶液灌流3 min,记录IKur。结果大鼠心房肌细胞超速激活的IKur电流特性:激活迅速,几乎无延迟现象,失活缓慢,峰电流呈现出外向整流特征,该电流约在-20 m V被激活,峰电流存在明显的电压依赖性,峰值(2.01±0.27)p A/p F。对于去极化至-10 m V^+20 m V时,伊布利特没有对IKur产生影响;伊布利特降低了+30 m V^+50 m V时IKur的电流密度数值,但无统计学意义。结论大鼠心房肌细胞的IKur电流特性:超速激活,无延迟现象,失活缓慢,峰电流呈现出外向整流特征,表现为显著的快速全动作电位时程的外向整流特征。2μg/L伊布利特灌流没有对IKur产生影响。Objective To study the characteristic of ultra-rapid delayed rectifier-potassium channel K current(IKur)in rat isolated atrial myocytes using whole-cell patch clamp technique,and the effect of Ibulitide on rat isolated atrialmyocytes.Methods Atrial myocytes of rats on an in vitro Langendorf perfusion system were obtained by double digestion(collagenase typeⅡ)method.Whole-cell patch-clamp recording technique was used to record IKur currents.The currentvoltage(I-V)curves of K+currents of atrial myocytes were fitted.With filled Ibulitide(2μg/L,filled3minutes),IKur wasrecorded.Results The Results showed that IKur was activated rapidly,almost no lag,and deactivation slowly.This currentwas activated at about-20mV,the peak current was present apparent voltage dependence.The peak current density was(2.01±0.27)pA/pF.After filled with Ibulite,this current was no any changed activation.Ibulite decreased the peak currentdensity from+30mV to+50mV,but no statistical significance.Conclusion The IKur of rats can activate rapidly with nodelays and inactivate slowly.This current is ultra-rapid delayed rectify outside current,and obvious displays thecharacteristic of outward rectification of whole action potential duration.The2μg/L Ibulitide shows no statisticalsignificance for this current.

关 键 词：延迟整流钾通道 大鼠 膜片钳术 伊布利特 

分 类 号：R337.5[医药卫生—人体生理学]