伊布利特对兔左心室中层细胞瞬间外向钾电流活性的影响  

Effects of ibutilide on transient outside potassium currents of left ventricle midmyocardial cells of rabbits

作　　者：宋春丽[1] 董巍[1] 赵刚[2] 刘红彬[1] 王丽娅[1] 吉丽[3] 

机构地区：[1]河北省石家庄市第三医院心内二科,050011 [2]河北省石家庄市第三医院超声科,050011 [3]河北省邯郸市第二医院心内科

出　　处：《河北医药》2013年第13期1925-1928,共4页Hebei Medical Journal

摘　　要：目的观察正常左心室中层心肌细胞(M细胞)瞬间外向钾电流(transient outside potassium current,Ito)的离子通道的变化,了解伊布利特抗室性心律失常的可能机制。方法新西兰纯种白兔60只,取其心脏行Langendorff灌流,以酶解法分离出单个左心室中层心肌细胞,以伊布利特10-6mol/L细胞外液及伊布利特10-5mol/L细胞外液对M细胞进行灌注,以膜片钳技术分别记录Ito的电流密度、电流-电压曲线(I-V)、失活曲线、失活后再恢复等变化,和对照组进行对比。结果 +60mV电流密度对照组为(17.4±5.2)pA/pF(n=14cells),10-6mol/L组(n=14cells)为(6.0±1.2)pA/pF,与对照组相比下降明显(P<0.01)。10-5mol/L组(n=14cells)为(4.5±1.1)pA/pF,与对照组比较有明显下降(P<0.01)。10-5mol/L组与10-6mol/L组比较差异有统计学意义(P<0.01)。I-V曲线比较显示伊布利特组I-V曲线均下移。伊布利特组与对照组相比,失活曲线明显左移(P<0.05或P<0.01),10-6mol/L组与10-5mol/L组半数最大失活电压与对照组比较下降显著(P<0.01)。Ito失活后再恢复明显减慢。结论伊布利特呈浓度依赖性抑制正常左心室中层心肌细胞Ito电流,可能是伊布利特临床上抗心律失常作用的机制之一。Objective To observe the changes of ion channel of transient outside potassium current （Ito） of left ventricular middle layer cells （M cells ） of rabbits in order to investigate the possible mechanism of anti-ventricular arrhythmia effect of ibutilide. Methods Sixty New Zealand white rabbits were enrolled in the study. The rabbits＇ hearts were cannulated via aorta and mounted on a Langendorff apparatus, then were perfused retrogradely. Single left ventricle midmyocardial cell was isolated by enzymolysis and was perfused with 10-6 mol/L and 10-5 mol/L ibutilide solution （10-6 mol/L ibutilide group and 10-2 mol/L ibutilide group）, respectively. Then patch clamp technique was used to record the changes of electric current density, electric current-voltage curve （ I-V curve）, inactivation curve and recovery after inactivation of Ito, which were compared with those in control group. Results The electric current density （ ＋ 60 mV） in 10 -6 mol/L ibutilide group was 6.0 ＋ 1.2 pA/ pF （ n = 14 cells） ,which was significantly decreased,as compared with 17.4 -＋ 5.2 pA/pF （ n = 14 cells） in control group （ P 〈 0.01 ）, which was （4.5 ＋ 1.1 ） pA/pF （ n = 14 cells） in 10-5 mol/L ibutilide group and was also significantly decreased （P 〈 0. 01 ）, furthermore, there was a significant difference between 10-5 mol/L ibutilide group and 10-6 mol/L ibutilide group （ P 〈 0.01 ）. The I-V curves in ibutilide groups were decreased, as compared with that in control group. As compared with that in control group, the inactivation curves in ibutilide groups were obviously shifted to left （ P 〈 0.05 or P 〈 0.01 ）. The half maximum inactivation voltages in ibutilide groups were significantly decreased, as compared with that in control group （ P 〈 0. 01 ）, and recovery after inactivation of Ito was obviously slower. Conclusion Ibutilide inhibits Ito electric current of normal left ventricle midmyocardial cells of rabbits in a concentration dependent manner,which maybe o

关 键 词：伊布利特 钾通道 瞬间外向钾电流 膜片钳 兔 

分 类 号：R541.7[医药卫生—心血管疾病]