Electrophysiological and pharmacological characterization of peripheral benzodiazepine receptors in a guinea pig heart preparation

Life Sci. 1984 Aug 27;35(9):953-62. doi: 10.1016/0024-3205(84)90661-1.

Abstract

RO5-4864 decreased in a dose-dependent manner, from 3 X 10(-9) M to 3 X 10(-6) M, the duration of intracellular action potential and the contractility in a guinea pig preparation. Diazepam was less effective and clonazepam inactive. The effects of RO5-4864 were GABA-independent and antagonized by PK 11195 but not by the selective antagonist of the brain type benzodiazepine receptors RO15-1788. These results show the pharmacological relevance of peripheral type benzodiazepine binding sites at the cardiac level.

MeSH terms

  • Action Potentials / drug effects
  • Animals
  • Benzodiazepinones / pharmacology*
  • Clonazepam / pharmacology
  • Convulsants / pharmacology*
  • Diazepam / pharmacology
  • Dose-Response Relationship, Drug
  • Electric Stimulation
  • Flumazenil
  • Guinea Pigs
  • Heart / drug effects
  • In Vitro Techniques
  • Isoquinolines / pharmacology*
  • Myocardial Contraction / drug effects
  • Myocardium / metabolism*
  • Receptors, Cell Surface / metabolism*
  • Receptors, GABA-A

Substances

  • Benzodiazepinones
  • Convulsants
  • Isoquinolines
  • Receptors, Cell Surface
  • Receptors, GABA-A
  • 4'-chlorodiazepam
  • Flumazenil
  • Clonazepam
  • Diazepam
  • PK 11195