Effect of BAY y 5959 on myocardial function and metabolism in normal and failing hearts

Koji Todaka, Jie Wang, Geng Hua Yi, Anguo Gu, Shu Ming Zhu, Hui Zhang, Daniel Burkhoff

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3 Citations (Scopus)

Abstract

BAY y 5959 is a dihydropyridine derivative with positive inotropic actions mediated by a direct increase in intracellular calcium. We characterized the direct myocardial actions of this new agent in hearts isolated from seven normal dogs and from five dogs with repeated coronary microembolization-induced heart failure. Inotropic actions of BAY y 5959 were accompanied by little effect on duration of contraction and by prolongation of the monophasic action potential (MAP); in contrast, isoproterenol decreased contraction and MAP durations. Whereas inotropic responsiveness to isoproterenol was blunted in embolized hearts, these actions of BAY y 5959 were relatively preserved in the heart failure state. Isoproterenol increased heart rate, whereas BAY y 5959 had little effect. Changes in coronary vascular resistance also decreased similarly for isoproterenol and BAY y 5959. Finally, for comparable inotropy, increases in myocardial oxygen consumption were similar for isoproterenol and for BAY y 5959. In summary, preserved inotropic responsiveness and lack of positive chronotropic actions are two clinically favorable features of this type of inotropic agents compared with a typical β-adrenergic agonist.

Original languageEnglish
JournalAmerican Journal of Physiology - Heart and Circulatory Physiology
Volume274
Issue number5 43-5
Publication statusPublished - May 1 1998
Externally publishedYes

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All Science Journal Classification (ASJC) codes

  • Physiology
  • Cardiology and Cardiovascular Medicine
  • Physiology (medical)

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