Incorporated sarcolemmal fish oil fatty acids shorten pig ventricular action potentials.
Cardiovasc Res
; 70(3): 509-20, 2006 Jun 01.
Article
em En
| MEDLINE
| ID: mdl-16564514
ABSTRACT
BACKGROUND:
Omega-3 polyunsaturated fatty acids (omega3-PUFAs) from fish oil reduce the risk of sudden death presumably by preventing life-threatening arrhythmias. Acutely administered omega3-PUFAs modulate the activity of several cardiac ion channels, but the chronic effects of a diet enriched with fish oil leading to omega3-PUFA-incorporation into the sarcolemma on membrane currents are unknown.METHODS:
Pigs received a diet either rich in omega3-PUFAs or in omega9-fatty acids for 8 weeks. Ventricular myocytes (VMs) were isolated and used for patch-clamp studies.RESULTS:
omega3-VMs contained higher amounts of omega3-PUFAs and had a shorter action potential (AP) with a more negative plateau than control VM. In omega3 VMs, L-type Ca(2+) current (I(Ca,L)) and Na(+)-Ca(2+) exchange current (I(NCX)) were reduced by approximately 20% and 60%, respectively, and inward rectifier K(+) current (I(K1)) and slow delayed rectifier K(+) current (I(Ks)) were increased by approximately 50% and 70%, respectively, compared to control. Densities of rapid delayed rectifier K(+) current, Ca(2+)-activated Cl(-) current, and Na(+) current (I(Na)) were unchanged, although voltage-dependence of I(Na) inactivation was more negative in omega3 VMs.CONCLUSIONS:
A fish oil diet increases omega3-PUFA content in the ventricular sarcolemma, decreases I(Ca,L) and I(NCX), and increases I(K1) and I(Ks), resulting in AP shortening. Incorporation of omega3-PUFAs in the sarcolemma may have consequences for arrhythmias independent of circulating omega3-PUFAs.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Sarcolema
/
Potenciais de Ação
/
Óleos de Peixe
/
Ácidos Graxos Ômega-3
/
Miócitos Cardíacos
/
Dieta
Limite:
Animals
Idioma:
En
Revista:
Cardiovasc Res
Ano de publicação:
2006
Tipo de documento:
Article
País de afiliação:
Holanda