[二十二碳六烯酸对大鼠心室肌细胞钠通道电流和瞬时外向钾通道电流的影响]

[Effects of docosahexaenoic acid on sodium channel current and transient outward potassium channel current in rat ventricular myocytes].

作者信息

Lai Li-hong, Dong Ping-shuan, Li Zhuan-zhen, Li Zhi-juan, Wang Ru-xing, Jiang Wen-ping

机构信息

Department of Cardiology, First Affiliated Hospital of Henan University of Science and Technology, Luoyang 471003, China.

出版信息

Zhonghua Xin Xue Guan Bing Za Zhi. 2011 May;39(5):451-6.

PMID:21781602

Abstract

OBJECTIVE

To investigate the effects of docosahexaenoic acid (DHA) on sodium channel current (I(Na)) and transient outward potassium channel current (I(to)) in rat ventricular myocytes and to evaluate potential anti-arrhythmic mechanisms of DHA.

METHODS

I(Na) and I(to) of individual ventricular myocytes were recorded by patch-clamp technique in whole-cell configuration at room temperature. Effects of DHA at various concentrations (0, 20, 40, 60, 80, 100 and 120 micromol/L) on I(Na) and I(to) were observed.

RESULTS

(1) I(Na) was blocked in a concentration-dependent manner by DHA, stably inactivated curves were shifted to the left, and recover time from inactivation was prolonged while stably activated curves were not affected by DHA. At -30 mV, I(Na) was blocked to (1.51 ± 1.32)%, (21.13 ± 4.62)%, (51.61 ± 5.73)%, (67.62 ± 6.52)%, (73.49 ± 7.59)% and (79.95 ± 7.62)% in the presence of above DHA concentrations (all P < 0.05, n = 20), and half-effect concentration (EC(50)) of DHA on I(Na) was (47.91 ± 1.57)micromol/L. (2) I(to) were also blocked in a concentration-dependent manner by DHA, stably inactivated curves were shifted to the left, and recover time from inactivation was prolonged with increasing concentrations of DHA, and stably activated curves were not affected by DHA. At +70 mV, I(to) was blocked to (2.61 ± 0.26)%, (21.79 ± 4.85)%, (63.11 ± 6.57)%, (75.52 ± 7.26)%, (81.82 ± 7.63)% and (84.33 ± 8.25)%, respectively, in the presence of above DHA concentrations (all P < 0.05, n = 20), and the EC(50) of DHA on I(to) was (49.11 ± 2.68)micromol/L.

CONCLUSION

The blocking effects of DHA on APD and I(to) may serve as one of the anti-arrhythmia mechanisms of DHA.

摘要

目的

研究二十二碳六烯酸（DHA）对大鼠心室肌细胞钠通道电流（I(Na)）和瞬时外向钾通道电流（I(to)）的影响，并评估DHA潜在的抗心律失常机制。

方法

采用膜片钳全细胞记录技术在室温下记录单个心室肌细胞的I(Na)和I(to)。观察不同浓度（0、20、40、60、80、100和120 μmol/L）的DHA对I(Na)和I(to)的影响。

结果

（1）DHA以浓度依赖性方式阻断I(Na)，稳态失活曲线左移，失活后恢复时间延长，而稳态激活曲线不受DHA影响。在-30 mV时，上述DHA浓度下I(Na)分别被阻断至(1.51 ± 1.32)%、(21.13 ± 4.62)%、(51.61 ± 5.73)%、(67.62 ± 6.52)%、(73.49 ± 7.59)%和(79.95 ± 7.62)%（均P < 0.05，n = 20），DHA对I(Na)的半数效应浓度（EC(50)）为(47.91 ± 1.57) μmol/L。（2）DHA也以浓度依赖性方式阻断I(to)，稳态失活曲线左移，随着DHA浓度增加失活后恢复时间延长，稳态激活曲线不受DHA影响。在+70 mV时，上述DHA浓度下I(to)分别被阻断至(2.6I ± 0.26)%、(21.79 ± 4.85)%、(63.11 ± 6.57)%、(75.52 ± 7.26)%、(81.82 ± 7.63)%和(84.33 ± 8.25)%（均P < 0.05，n = 20），DHA对I(to)的EC(50)为(49.11 ± 2.68) μmol/L。