Effects of docosahexaenoic acid on ion channels of rat coronary artery smooth muscle cells
10.3760/cma.j.issn.0253-3758.2012.05.015
- VernacularTitle:二十二碳六烯酸对大鼠冠状动脉平滑肌细胞离子通道的影响
- Author:
Ping-Shuan DONG
1
;
Li-Hong LAI
;
Hong-Lei WANG
;
Shi-Ying XING
;
Ji-Hong ZHU
;
Xu-Ming YANG
;
Shao-Xin WANG
;
Zhuan-Zhen LI
;
Xi-Yan SHANG
Author Information
1. 河南科技大学附属第一医院
- Keywords:
Coronary vessels;
Myocytes,smooth muscle;
Docosahexaenoic acids;
Large-conductance calcium-activated potassium channels;
Potassium channels,voltage-gated
- From:
Chinese Journal of Cardiology
2012;40(5):421-426
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the effects of docosahexaenoic acid (DHA) on large-conductance Ca2 + -activated K+ ( BKCa ) channels and voltage-dependent K+ ( Kv ) channels in rat coronary artery smooth muscle cells ( CASMCs ),and evaluate the vasorelaxation mechanisms of DHA.Methods BKCa and Kv currents in individual CASMC were recorded by patch-clamp technique in whole-cell configuration.Effects of DHA at various concentrations (0,10,20,40,60 and 80 μ mol/L) on BKCa and Kv channels were observed.Results ( 1 ) DHA enhanced IBKCa and BKCa tail currents in a concentration-dependent manner while did not affect the stably activated curves of IBKCa+ IBKCa current densities were (68.2±22.8),(72.4 ±24.5),(120.4 ±37.9),(237.5 ±53.2),(323.6 ±74.8) and (370.6 ±88.2 )pA/pF respectively (P ＜ 0.05,n =30) with the addition of 0,10,20,40,60 and 80 μmol/L DHA concentration,and half-effect concentration ( EC50 ) of DHA was (36.22 ± 2.17 ) μmol/L.(2) IKv and Kv tail currents were gradually reduced,stably activated curves of IKv were shift to the right,and stably inactivated curves were shifted to the left in the presence of DHA.IKv current densities were (43.9 ±2.3),(43.8±2.3),(42.9±2.0),(32.3±1.9),(11.7±1.5) and (9.6 ±1.2)pA/pF respectively(P＜0.05,n =30) post treatment with 0,10,20,40,60 and 80 μmol/L DHA under manding potential equal to +50 mV,and EC50 of DHA was (44.19 ±0.63) μmol/L.Conclusion DHA can activate BKCa channels and block Kv channels in rat CASMCs,the combined effects on BKCa and Kv channels lead to the vasodilation effects of DHA on vascular smooth muscle cells.
