RESUMEN

In situ microelectrode examination of rat right atrium showed that in physiologically prestretched tissue, NO donor SNAP modifies the repolarization phase of cardiomyocyte AP in a "hump-like" way provoking the development of arrhythmia. Gadolinium both prevents and eliminates this effect attesting to involvement of stretch-activated channels in the development of NO-induced abnormalities. Elevation of SNAP concentration or further stretch of the tissue (presumably, it increases NO concentration) eliminated the hump depolarization induced by moderate SNAP stimulation. Thus, low NO opens the stretch-activated channels while high NO inactivates them.

Asunto(s)

Atrios Cardíacos/efectos de los fármacos , Mecanotransducción Celular/efectos de los fármacos , Óxido Nítrico/metabolismo , Potenciales de Acción/efectos de los fármacos , Animales , Gadolinio , Atrios Cardíacos/metabolismo , Masculino , Ratas , Ratas Wistar , S-Nitroso-N-Acetilpenicilamina/farmacología