Inotropic effects of angiotensin II on human cardiac muscle in vitro

Christine Schomisch Moravec, Mark D. Schluchter, Lata Paranandi, Barbara Czerska, Robert W. Stewart, Eliot Rosenkranz, Meredith Bond

Research output: Contribution to journalArticle

116 Scopus citations

Abstract

The direct effects of angiotensin II (Ang II) on human cardiac muscle were investigated using isolated trabecular muscles from failing and functionally normal hearts. Atrial and ventricular trabeculae were studied. Results demonstrated a positive inotropic effect of Ang II on human cardiac muscle. Comparison of the effects of Ang II among groups indicated that the responsiveness tended to be greater in atrial and normal muscle compared with failing muscle. Results of this study also demonstrated heterogeneity in the responsiveness to Ang II among human muscles, which was not correlated with patient age, sex, diagnosis, prior treatment with angiotensin converting enzyme inhibitor, or heart function. A significant correlation between response to Ang II and response to isoproterenol was demonstrated in failing ventricular trabeculae, which may suggest that defects in β-adrenergic responsiveness in the failing human ventricle are accompanied by a loss of responsiveness to Ang II. Studies were extended to the Syrian cardiomyopathic hamster and its control. A dose-dependent inotropic response occurred in normal hamster ventricular muscle but was significantly diminished in cardiomyopathic muscle. Ang II did not shorten the timing of contraction, and pretreatment with adrenergic-blocking agents did not shift the dose-response curve, indicating that the response was not cyclic AMP mediated. This study demonstrates for the first time that Ang II can exert an inotropic effect directly on human cardiac muscle and confirms that there is a direct effect of Ang II on hamster cardiac muscle. The study further suggests, however, that the inotropic response to Ang II in cardiac muscle is heterogeneous and may be diminished by heart failure.

Original languageEnglish (US)
Pages (from-to)1973-1984
Number of pages12
JournalCirculation
Volume82
Issue number6
DOIs
StatePublished - Jan 1 1990
Externally publishedYes

Keywords

  • Angiotensin II
  • Cardiac muscle
  • Cardiomyopathy
  • Syrian cardiomyopathic hamster

ASJC Scopus subject areas

  • Physiology
  • Cardiology and Cardiovascular Medicine

Fingerprint Dive into the research topics of 'Inotropic effects of angiotensin II on human cardiac muscle in vitro'. Together they form a unique fingerprint.

  • Cite this

    Moravec, C. S., Schluchter, M. D., Paranandi, L., Czerska, B., Stewart, R. W., Rosenkranz, E., & Bond, M. (1990). Inotropic effects of angiotensin II on human cardiac muscle in vitro. Circulation, 82(6), 1973-1984. https://doi.org/10.1161/01.CIR.82.6.1973