Effects of docosahexaenoic acid on action potential and transient outward potassium current on ventricular myocytes of Sprague-Dawley rat
10.3760/cma.j.issn.0253-3758.2009.02.004
- VernacularTitle: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
- Author:
Ru-Xing WANG
1
;
Xiao-Rong LI
;
Li-Hong LAI
;
Xiao-Qing WU
;
Yan-Fen CHEN
;
Jian-Ping SONG
;
Xiang-Jun YANG
;
Wen-Ping JIANG
Author Information
1. 南京医科大学附属无锡人民医院
- Keywords:
Anti-arrhythmia agents;
Potassium channels;
Action potentials;
Patch-clamp techniques;
Docosahexaenic acid
- From:
Chinese Journal of Cardiology
2009;37(2):108-111
- CountryChina
- Language:Chinese
-
Abstract:
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 0 μmol/L to 30 μmol/L, while APDs were gradually prolonged in proportion with increasing DHA concentrations from 30 μmol/L to 200 μmol/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 100 μmol/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 200 μmoL/L DHA. (2) Ito was gradually reduced with the increasing DHA concentrations from 10 μmol/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 60 μmol/L and its half-inhibition concentration was 58. 3 μmol/L. Conclusion APDs are gradually prolonged while Ito reduced with increasing concentrations of DHA which might contribute to the anti-arrhythmia mechanisms of DHA.
