Alpha-adrenoceptor-mediated positive inotropic effect of phenylephrine in isolated human ventricular myocardium

Eur J Pharmacol. 1984 Apr 6;99(4):345-7. doi: 10.1016/0014-2999(84)90144-4.


In isolated human ventricular myocardium the alpha-adrenoceptor agonist phenylephrine had a positive inotropic effect in preparations from 9 of 14 patients. This effect was seen in the presence of the beta-adrenoceptor-blocking agent propranolol but was nearly abolished by the alpha-adrenoceptor blocking agent prazosin. In contrast to the beta-adrenoceptor-mediated positive inotropic effect, the effect of phenylephrine was accompanied by a prolongation of the isometric contraction. The results suggest that alpha-adrenoceptors exist in human ventricular myocardium.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Female
  • Humans
  • In Vitro Techniques
  • Isoproterenol / pharmacology
  • Male
  • Middle Aged
  • Myocardial Contraction / drug effects*
  • Phenylephrine / pharmacology*
  • Prazosin / pharmacology
  • Propranolol / pharmacology
  • Receptors, Adrenergic, alpha / drug effects*


  • Receptors, Adrenergic, alpha
  • Phenylephrine
  • Propranolol
  • Isoproterenol
  • Prazosin