Your browser doesn't support javascript.
loading
Late exercise training improves non-uniformity of transmural myocardial function in rats with ischaemic heart failure.
Aït Mou, Younss; Reboul, Cyril; Andre, Lucas; Lacampagne, Alain; Cazorla, Olivier.
Afiliación
  • Aït Mou Y; INSERM U637, Physiopathologie Cardiovasculaire, CHU Arnaud de Villeneuve, 34295 Montpellier Cedex 5, Montpellier, France.
Cardiovasc Res ; 81(3): 555-64, 2009 Feb 15.
Article en En | MEDLINE | ID: mdl-18703535
ABSTRACT

AIMS:

The exercise-induced beneficial mechanisms after long-term myocardial infarction (MI) are incompletely understood. The present study evaluated the effect of treadmill exercise training (5 weeks), started at a late stage of heart failure (HF) (13 weeks post-MI), on rat left ventricle remodelling and dysfunction of the regional global and cellular contractile functions. METHODS AND

RESULTS:

In vivo echocardiography confirmed that sub-endocardial (ENDO) layers contract more (+86%) and faster (+50%) than the sub-epicardial (EPI) layers. This gradient was lost in MI rats due to a predominant reduction in the ENDO layer contractility. Exercise partially restored the amplitude and velocity of ENDO contraction, resulting in a partial recovery of the pump function indexed by the aortic blood-flow velocity time integral. At the cellular level, MI impaired ENDO contractile properties by reducing cell shortening (10-7%), calcium transient, and myofilament Ca(2+) sensitivity. These alterations were normalized by exercise. Sarcoplasmic reticulum Ca(2+)-ATPase (SERCA)2a expression and myosin light chain (MLC)-2 phosphorylation in ENDO cells were significantly reduced after MI and were restored by exercise. The EPI layer was only slightly reduced in vivo without cellular alterations.

CONCLUSION:

This study shows that exercise performed at a late stage after MI restored a transmural non-uniformity of myocardium lost during HF. Recoveries of Ca(2+) homeostasis and myofilament function of cardiomyocytes contribute to this beneficial effect.
Asunto(s)

Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Función Ventricular Izquierda / Isquemia Miocárdica / Remodelación Ventricular / Terapia por Ejercicio / Insuficiencia Cardíaca / Contracción Miocárdica Tipo de estudio: Etiology_studies / Prognostic_studies Límite: Animals Idioma: En Revista: Cardiovasc Res Año: 2009 Tipo del documento: Article País de afiliación: Francia

Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Función Ventricular Izquierda / Isquemia Miocárdica / Remodelación Ventricular / Terapia por Ejercicio / Insuficiencia Cardíaca / Contracción Miocárdica Tipo de estudio: Etiology_studies / Prognostic_studies Límite: Animals Idioma: En Revista: Cardiovasc Res Año: 2009 Tipo del documento: Article País de afiliación: Francia