CIC   05421
CENTRO DE INVESTIGACIONES CARDIOVASCULARES "DR. HORACIO EUGENIO CINGOLANI"
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Hypotonic Swelling Promotes Nitric Oxide Release in Rat Cardiac Ventricular Myoycte: Impact on Swelling-Induced Negative Inotropic Effect
Autor/es:
MALENA MORELL, LUIS GONANO, MARISA SEPÚLVEDA AND MARTIN VILA PETROFF
Lugar:
New London
Reunión:
Congreso; Gordon research conference: cardiac regulatory mechanisms; 2012
Institución organizadora:
Gordon Conferences
Resumen:
Cell swelling is known to contribute to the pathophysiology of ischemia and reperfusion by promoting contractile dysfunction and predisposing the heart for arrhythmias. However, the underlying subcellular mechanisms of swelling-induced contractile dysfunction are still not fully understood. We have previously shown that cardiac cell stretch promotes nitric oxide (NO) release favoring spontaneous SR Ca2+ release. Here we investigate whether hypotonic swelling promotes nitric oxide release and if so, whether it contributes to cardiac cell swelling-induced contractile dysfunction. Treating rat cardiac myocytes, loaded with the NO sensor DAF-2, with a hypotonic solution, increased cell volume, reduced myocyte contraction amplitude and significantly increased DAF-2 fluorescence. When cells were exposed to the hypotonic solution supplemented with 2.5 mM of the NO synthase inhibitor L-Name, cell swelling occurred in the absence of NO release. Interestingly, swelling-induced negative inotropic effect was exacerbated in the presence of L-Name. These results suggest that hypotonic swelling promotes NO release which reduces contractile dysfunction. Taken together, these findings suggest a novel mechanism for NO release in cardiac myocytes with putative pathophysiological relevance in the context of ischemia and reperfusion, where it may serve a cardioprotective role by reducing the extent of contractile dysfunction.
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