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Increasing DHA and EPA Concentrations Prolong Action Potential Durations and Reduce Transient Outward Potassium Currents in Rat Ventricular Myocytes
Author(s) -
Li HongXia,
Wang RuXing,
Li XiaoRong,
Guo Tao,
Wu Ying,
Guo SuXia,
Sun LiPing,
Yang ZhenYu,
Yang XiangJun,
Jiang WenPing
Publication year - 2011
Publication title -
lipids
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.601
H-Index - 120
eISSN - 1558-9307
pISSN - 0024-4201
DOI - 10.1007/s11745-010-3503-3
Subject(s) - potassium , myocyte , chemistry , clinical chemistry , transient (computer programming) , cardiac transient outward potassium current , lipidology , potassium channel , medicine , electrophysiology , patch clamp , biochemistry , organic chemistry , computer science , operating system
The goal of this study was to determine the mechanisms of n‐3 polyunsaturated fatty acids (n‐3 PUFA) on anti‐arrhythmias and prevention of sudden death. The calcium‐tolerant Sprague–Dawley rat ventricular myocytes were isolated by enzyme digestion. Effects of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) on action potentials and transient outward potassium currents ( I to ) of epicardial ventricular myocytes were investigated using whole‐cell patch clamp techniques. Action potential durations (APDs) and I to were observed in different concentrations of DHA and EPA. APD 25 , APD 50 , and APD 90 with 0.1 μmol/L DHA and EPA were prolonged less than 15% and 10%. However, APDs were prolonged in concentration‐dependent manners when DHA and EPA were more than 1 μmol/L. APD 25 , APD 50 , and APD 90 were 7.7 ± 2.0, 21.2 ± 3.5, and 100.1 ± 9.8 ms respectively with 10 μmol/L DHA, and 7.2 ± 2.5, 12.8 ± 4.2, and 70.5 ± 10.7 ms respectively with 10 μmol/L EPA. I to currents were gradually reduced with the increased concentrations of DHA and EPA from 1 to 100 μmol/L, and their half‐inhibited concentrations were 2.3 ± 0.2 and 3.8 ± 0.6 μmol/L. The results showed APDs were prolonged and I to current densities were gradually reduced with the increased concentrations of DHA and EPA. The anti‐arrhythmia mechanisms of n‐3 PUFA are complex, however, the effects of n‐3 PUFA on action potentials and I to may be one of the important mechanisms.