[Mechanism related to docosahexaenoic acid induced large conductance calcium-activated potassium channel currents increase in coronary smooth muscle cells].
Zhonghua Xin Xue Guan Bing Za Zhi
; 39(4): 348-52, 2011 Apr.
Article
en Zh
| MEDLINE
| ID: mdl-21624312
ABSTRACT
OBJECTIVE:
To investigate the mechanism of enhanced large conductance calcium-activated potassium channel currents (BK) in coronary smooth muscle cells (SMCs) by docosahexaenoic acid (DHA).METHODS:
Coronary SMCs were isolated by enzyme digestion. Potassium channels in coronary SMCs were identified by applications of different potassium blockers. Effects of DHA and its metabolite 16, 17-epoxydocosapentaenoic acid (16, 17-EDP) on BK channels in the absence and presence of cytochrome P450 epoxygenase inhibitor SKF525A were studied by patch clamp in whole-cell configuration.RESULTS:
BK channels were widely distributed in SMCs, and BK currents in normal SMCs accounted for (64.2 ± 2.7)% of total potassium currents (n = 20). DHA could activate BK channels, and its 50% effective concentration (EC(50)) was (0.23 ± 0.03) µmol/L, however, the effect of DHA on BK channels was abolished after SMCs were incubated with cytochrome P450 epoxygenase inhibitor SKF525A. 16, 17-EDP, a metabolite of DHA, could reproduce the effects of DHA on BK channels, and its EC(50) was (19.7 ± 2.8) nmol/L.CONCLUSION:
DHA and metabolites can activate BK channels and dilate coronary arteries through activating cytochrome P450 epoxygenase pathway.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Ácidos Docosahexaenoicos
/
Vasos Coronarios
/
Miocitos del Músculo Liso
/
Canales de Potasio de Gran Conductancia Activados por el Calcio
Límite:
Animals
Idioma:
Zh
Revista:
Zhonghua Xin Xue Guan Bing Za Zhi
Año:
2011
Tipo del documento:
Article
País de afiliación:
China