Effects of polyunsaturated fatty acids on cardiac voltage-activated K(+) currents in adult ferret cardiomyocytes / 生理学报
Acta Physiologica Sinica
;
(6): 271-281, 2002.
Article
Dans Anglais
| WPRIM
| ID: wpr-279298
ABSTRACT
This study was carried out in adult ferret cardiomyocytes to investigate the effects of the n-3 polyunsaturated fatty acids (PUFAs) on voltage-gated K(+) currents. We report that the two outward K(+) currents the transient outward K(+) current (I(to)) and the delayed rectifier K(+) current (I(K)), are both inhibited by the n-3 PUFAs, while the inwardly rectifying K(+) current (I(K1)) is unaffected by the n-3 PUFAs. Docosahexaenoic acid (C226n-3, DHA) produced a concentration dependent suppression of I(to) and I(K) in adult ferret cardiomyocytes with an IC(50) of 7.5 and 20 micromol/L, respectively; but not I(K1). In addition, eicosapentaenoic acid (C205n-3, EPA) had the effects on the three K(+) channels similar to DHA. Arachidonic acid (C204n-6, AA) at 5 or 10 micromol/L, after an initial inhibitory effect on I(K), caused an activation of I(K),AA which was prevented by pretreatment with indomethacin, a cyclooxygenase inhibitor. Monounsaturated and saturated fatty acids, which are not antiarrhythmic, lack the effects on these K(+) currents. Our results demonstrate that the n-3 PUFAs inhibit cardiac I(to) and I(K) with much less potency compared to their effects on cardiac Na(+) and Ca(2+) currents as we reported previously. This inhibition of the cardiac ion currents by the n-3 PUFAs may contribute to their antiarrhythmic actions.
Texte intégral:
Disponible
Indice:
WPRIM (Pacifique occidental)
Sujet Principal:
Pharmacologie
/
Acide eicosapentanoïque
/
Acide docosahexaénoïque
/
Acide arachidonique
/
Canaux potassiques voltage-dépendants
/
Myocytes cardiaques
/
Relation dose-effet des médicaments
/
Furets
/
Métabolisme
Limites du sujet:
Animaux
langue:
Anglais
Texte intégral:
Acta Physiologica Sinica
Année:
2002
Type:
Article
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