Postischemic mechanoenergetic inefficiency is related to contractile dysfunction and not altered metabolism.
Am J Physiol Heart Circ Physiol
; 281(6): H2645-53, 2001 Dec.
Article
em En
| MEDLINE
| ID: mdl-11709434
ABSTRACT
Mechanoenergetic inefficiency in postischemic nonnecrotic myocardium may partly be explained by an increased fatty acid (FA) oxidation rate. In the present study, left ventricular (LV) postischemic energy transfer was characterized in 10 intact anesthetized pigs. The LV was stunned by 11 brief left main coronary artery occlusions/reperfusions (20-min accumulated ischemia). Seven pigs served as time controls. The relationship between myocardial oxygen consumption (MVO(2)) and LV pressure-volume area (PVA) was assessed. [(14)C]glucose and [(3)H]oleate markers were used to discriminate between glucose and FA consumption. In stunned hearts, severe postischemic dysfunction was observed, and contractile efficiency was reduced (increased MVO(2)-PVA slope, P = 0.001). Unloaded (nonmechanical) MVO(2) was not affected by ischemia. We observed only a small transient increase in FA preference and conclude that the contribution from increased FA utilization to postischemic mechanoenergetic inefficiency is insignificant. Disrupted postischemic chemical-to-mechanical energy transfer in vivo is, therefore, related to inefficient energy utilization in the contractile apparatus.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Miocárdio Atordoado
/
Metabolismo Energético
/
Contração Miocárdica
Limite:
Animals
Idioma:
En
Revista:
Am J Physiol Heart Circ Physiol
Assunto da revista:
CARDIOLOGIA
/
FISIOLOGIA
Ano de publicação:
2001
Tipo de documento:
Article
País de afiliação:
Noruega