title: Anticholinergic action of pirenzepine (Gastrozepin) on isolated gastrointestinal tract smooth muscles.
abstract: The effects of pirenzepine, a new anti-ulcer drug, have been examined on acetylcholine (ACh)-induced contractions of the guinea-pig isolated ileum, rat colon, rainbow lizard rectum, and chick isolated oesophagus. Pirenzepine (10(-9)-10(-6) M), like atropine (2.5 x 10(-10)-10(-6) M) competitively blocked the contractile effects of acetylcholine on all the isolated gastrointestinal tract smooth muscles examined. The pA2 values for pirenzepine and atropine against acetylcholine on all the muscle preparations were not significantly different (P greater than 0.05). It is concluded that the anti-ulcer action of pirenzepine might be due, at least in part, to its (anticholinergic) muscarinic cholinoceptor blocking activity.
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001570:Benzodiazepinones / Q000494:pharmacology*; D002645:Chickens; D003106:Colon / Q000187:drug effects; D005260:Female; D006168:Guinea Pigs; D007082:Ileum / Q000187:drug effects; D066298:In Vitro Techniques; D008116:Lizards; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects*; D010276:Parasympatholytics; D010890:Pirenzepine; D051381:Rats; D012007:Rectum / Q000187:drug effects
chemical_list: D001570:Benzodiazepinones; D010276:Parasympatholytics; D010890:Pirenzepine; D000109:Acetylcholine