Influence of monoamine oxidase inhibitor on contractility of isolated rat hearts

Abstract

Following the suggestion that monoamine oxidase inhibitor might interfere with potentiation of cardiac contractions, the influence of 1-iso-nicotinyl-2-isopropyl-hydrazide and 1-pivaloyl-2-benzyl-hydrazine on postextrasystolic increase of isotonic contractions in isolated perfused rat hearts was studied. It was found that mono-amine oxidase inhibitor did not change the increase in contractility following an interpolated or a noninterpolated premature beat. The metabolic process by which cardiac muscle varies its contractility with varying cycle length remains unknown.