Prejunctional alpha 2-adrenergic properties of S-3341 (dicyclopropylmethyl)amino-2-delta-2-oxazoline: a comparison with clonidine

Can J Physiol Pharmacol. 1987 Dec;65(12):2496-9. doi: 10.1139/y87-397.

Abstract

The prejunctional activities of S-3341 and clonidine have been studied in the transmural field-stimulated epididymal part of the rat vas deferens. Both S-3341 and clonidine inhibited these neuronally induced contractions. At high concentrations, these agonists induced spontaneous contractions in the preparation, which were abolished by 10(-7) M prazosin. The inhibitory effects of S-3341 and clonidine were antagonized in a competitive manner by rauwolscine and were found not to be modified in a statistically significant manner by 10(-7) M prazosin. The pA2 values of rauwolscine against S-3341 and clonidine were the same, indicating the receptors influenced by these drugs were the same also. However, the efficacy of S-3341 is lower than that of clonidine (by a factor of approximately 100). This lower efficacy of S-3341 at the prejunctional level could be linked to the lack of a sedative effect of this compound at therapeutic concentrations.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adrenergic alpha-Agonists / pharmacology*
  • Animals
  • Clonidine / pharmacology*
  • Electric Stimulation
  • In Vitro Techniques
  • Male
  • Muscle Contraction / drug effects
  • Muscle, Smooth / drug effects*
  • Muscle, Smooth / innervation
  • Neuromuscular Junction / drug effects*
  • Oxazoles / pharmacology*
  • Prazosin / pharmacology
  • Rats
  • Rats, Inbred WKY
  • Rilmenidine
  • Vas Deferens / drug effects
  • Vas Deferens / innervation
  • Vas Deferens / physiology
  • Yohimbine / pharmacology

Substances

  • Adrenergic alpha-Agonists
  • Oxazoles
  • Yohimbine
  • Clonidine
  • Rilmenidine
  • Prazosin