Selective antagonism by pirenzepine and N-methyl-scopolamine on muscarinic receptor subtypes of the rat vas deferens

Gen Pharmacol. 1988;19(3):417-20. doi: 10.1016/0306-3623(88)90039-0.

Abstract

1. The effects of pirenzepine and N-methyl-scopolamine on the responses to ACh in the isolated rat vas deferens were studied. 2. Pirenzepine was inactive at the M2-ACh receptor. 3. N-methyl-scopolamine was a competitive antagonist (pA2 = 8.76) at M2-ACh receptor, alone or in the presence of pirenzepine. 4. Pirenzepine and N-methyl-scopolamine were both non-competitive antagonists at M1-ACh receptor. 5. The mixture of pirenzepine and N-methyl-scopolamine did not alter the type of antagonism demonstrated by each drug at the M1-ACh receptor.

Publication types

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

MeSH terms

  • Animals
  • Male
  • Muscle Contraction / drug effects
  • Muscle, Smooth / drug effects*
  • Muscle, Smooth / innervation
  • N-Methylscopolamine
  • Parasympatholytics / pharmacology*
  • Pirenzepine / pharmacology*
  • Rats
  • Rats, Inbred Strains
  • Receptors, Muscarinic / drug effects*
  • Scopolamine Derivatives / pharmacology*
  • Vas Deferens / drug effects

Substances

  • Parasympatholytics
  • Receptors, Muscarinic
  • Scopolamine Derivatives
  • Pirenzepine
  • N-Methylscopolamine