Does pirenzepine distinguish between 'subtypes' of muscarinic receptors?
Pharmacological studies with pirenzepine were carried out on the isolated ileum and atrium of the guinea-pig and on the acid secretion from the isolated stomach of the mouse. Pirenzepine inhibited the bethanechol-evoked changes in all three organs in a dose-dependent manner. The slopes of the Schild-plots confirmed the competitive nature of the antagonism by pirenzepine. The estimated pA2-values were very similar. Based on these data, it might be concluded that pirenzepine is an anticholinoceptor compound without specific affinity for gastric muscarinic receptors.
D000818:Animals; D001285:Atropine / Q000494:pharmacology; D001570:Benzodiazepinones / Q000494:pharmacology*; D001626:Bethanechol Compounds / Q000494:pharmacology; D005753:Gastric Mucosa / Q000187:drug effects / Q000378:metabolism; D006168:Guinea Pigs; D066298:In Vitro Techniques; D051379:Mice; D009130:Muscle, Smooth / Q000187:drug effects; D009200:Myocardial Contraction / Q000187:drug effects; D010890:Pirenzepine; D011950:Receptors, Cholinergic / Q000187:drug effects*; D011976:Receptors, Muscarinic / Q000145:classification / Q000187:drug effects*
D001570:Benzodiazepinones; D001626:Bethanechol Compounds; D011950:Receptors, Cholinergic; D011976:Receptors, Muscarinic; D010890:Pirenzepine; D001285:Atropine