二十二碳六烯酸对Sprague-Dawley大鼠心室肌细胞动作电位和瞬时外向钾离子流的作用  

Effects of docosahexaenoic acid on action potential and transient outward potassium current on ventricular myocytes of Sprague-Dawley rat

作　　者：王如兴[1] 李肖蓉[1] 来利红[2] 吴小庆[1] 陈燕芬[1] 宋建平[2] 杨向军[2] 蒋文平[2] 

机构地区：[1]南京医科大学附属无锡人民医院心内科,江苏南京214023 [2]苏州大学附属第一医院心内科

出　　处：《中华心血管病杂志》2009年第2期108-111,共4页Chinese Journal of Cardiology

摘　　要：目的探讨二十二碳六烯酸（DHA）对Sprague-Dawley大鼠心室肌细胞动作电位（AP）和瞬时外向钾离子流（Ito）的作用。方法采用酶消化法获得大鼠耐钙心室肌细胞，以全细胞膜片钳技术分别记录加入DHA10、20、40、60、80、100、120和200μmol／L后大鼠心室肌细胞AP和Ito的变化。结果（1）当DHA浓度大于30μmol／L时，动作电位时程（APD）逐渐延长，且呈浓度依赖性（P〈0.05）；当DHA浓度侄0-30μmol／L时，随着DHA浓度增加，APD延长不明显（P〉0.05）；加入不同浓度DHA后，在5min内APD随时间延长而逐渐延长，5min后APD基本同定。（2）加入不同浓度DHA后，随着DHA浓度增加，Ito逐渐降低，DHA对Ito呈浓度依赖性阻滞（P〈0.05）。DHA对Ito半效抑制浓度为58.3μmol／L。结论当加入不同浓度DHA后，APD随着DHA浓度增加而逐渐延长，Ito逐渐降低，DHA对AP和Ito的影响可能是其抗心律失常作用的机制之一。Objective To investigate the effects of docosahexaenoic acid （DHA） on action potential （AP） and transient outward potassium current （Ito） on ventricular myocytes of Sprague-Dawley rat. Methods Calcium-tolerant ventricular myocytes were isolated by enzyme digestion. The changes of AP and Ito with increasing DHA at concentrations of 0, 10, 20, 40, 60, 80, 100, 120 and 200 μmol/L were recorded by whole-cell patch clamp configuration. Results （1） Action potential durations （APDs） were not affected by DHA at concentrations from 0μmol/L to 30μmol/L, while APDs were gradually prolonged in proportion with increasing DHA concentrations from 30μmol/L to 200μmol/L within 5 minutes and remained stable thereafter. APD25, APD50 and APD75 were （7. 7±2.0） ms, （21.2±3.5） ms, and （100.1±9.8） ms respectively at 100μmol/L DHA. APD25, APD50, and APD75 were （15.2±4.0） ms, （45.7±6.8） ms, and （215.6±15.7） ms respectively at 200μmol/L DHA. （2）Ito was gradually reduced with the increasing DHA concentrations from 10μmol/L to 200 μmol/L Ito was blocked by DHA in a dose-dependent manner. Ito current density was（30.1±7.2） pA/pF at DHA concentration of 60μmol/L and its half-inhibition concentration was 58.3μmol/L. Conclusion APDs are gradually prolonged while Ito reduced with increasing concentrations of DHA which might contribute to the anti-arrhythmia mechanisms of DHA.

关 键 词：抗心律失常药 钾通道 动作电位 膜片钳术 二十二碳六烯酸 

分 类 号：R686[医药卫生—骨科学]