天津医药

天津医药 ›› 2017, Vol. 45 ›› Issue (2): 168-171.doi: 10.11958/20161263

• 实验研究 • 上一篇    下一篇

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

李琼 1， 李健 2， 吴冬燕 1， 任静 1， 卢凤民 1， 许静 1   

  1. 1 天津市胸科医院 （邮编 300222）； 2 天津医科大学第二医院
  • 收稿日期:2016-11-02 修回日期:2017-01-07 出版日期:2017-02-15 发布日期:2017-02-14

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

LI Qiong1, LI Jian2, WU Dong-yan1, REN Jing1, LU Feng-min1, XU Jing1   

  1. 1 Tianjin Chest Hospital, Tianjin 300222, China; 2 Tianjin Medicine University Second Hospital
  • Received:2016-11-02 Revised:2017-01-07 Published:2017-02-15 Online:2017-02-14

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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 2 μg/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 mV 被激活， 峰电流存在明显的电压依赖性， 峰值 （2.01±0.27） pA/pF。对于去极化至-10 mV～+20 mV 时， 伊布利特没有对 IKur 产生影响； 伊布利特降低了+30 mV～+50 mV 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。2 μg/L 伊布利特灌流没有对 IKur 产生影响。

关键词: 延迟整流钾通道, 大鼠, 膜片钳术, 伊布利特

Abstract: 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 atrial myocytes. Methods Atrial myocytes of rats on an in vitro Langendorf perfusion system were obtained by double digestion (collagenase type Ⅱ) 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 (2 μg/L, filled 3 minutes), IKur was recorded. Results The Results showed that IKur was activated rapidly, almost no lag， and deactivation slowly. This current was activated at about -20 mV, 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 current density from +30 mV to +50 mV， but no statistical significance. Conclusion The IKur of rats can activate rapidly with no delays and inactivate slowly. This current is ultra- rapid delayed rectify outside current，and obvious displays the characteristic of outward rectification of whole action potential duration. The 2 µg/L Ibulitide shows no statistical significance for this current.

Key words: IKur, rat, patch clamp techniques, Ibulitide