Anisodamine inhibits non-selectively muscarinic receptors in isolated canine veins

Chin Med J (Engl). 1992 Jan;105(1):5-10.

Abstract

Organ chamber experiments were designed to determine the effects of anisodamine, an alkaloid structurally related to atropine, on prejunctional M2- and postjunctional M2-muscarinic receptors in isolated canine saphenous veins. The results showed that both acetylcholine-induced contraction and dilatation were inhibited in a competitive manner by anisodamine or atropine. The affinity of anisodamine for pre- and postjunctional muscarinic receptors was comparable (pKB = 7.78 and 7.86, respectively). However, compared with atropine, the affinity of anisodamine for prejunctional M2-receptors was about 1/8; while that for postjunctional M1-receptors was only 1/25 of that of atropine (pKB = 8.69 and 9.25, respectively for atropine). The data demonstrate that anisodamine is a non-selective muscarinic antagonist, a modulator rather than a vasodilator. The probable mechanisms involved are discussed.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Atropine / pharmacology
  • Dogs
  • In Vitro Techniques
  • Muscarinic Antagonists*
  • Muscle Contraction / drug effects
  • Saphenous Vein / drug effects*
  • Solanaceous Alkaloids / pharmacology*
  • Vasodilator Agents / pharmacology

Substances

  • Muscarinic Antagonists
  • Solanaceous Alkaloids
  • Vasodilator Agents
  • anisodamine
  • Atropine