Effect of serotonin on bethanechol-stimulated gastric acid secretion and gastric antral motility in dogs.
The purpose of the present study was to evaluate the effect of serotonin on bethanechol-stimulated gastric acid secretion and antral motility in conscious dogs with gastric fistula. Bethanechol stimulated the acid secretion dose-dependently and maintained the frequency and strength of the antral contractions at a high level. Serotonin inhibited the acid secretion dose-dependently, whereas the antral motility was stimulated. The acid inhibition was blocked by propranolol, and dose-response analysis showed inhibition of a non-competitive type. This study thereby shows that serotonin inhibits bethanechol-stimulated gastric acid secretion similarly to salmefamol (beta 2-adrenergic agonist)--that is, dose-dependently and non-competitively. Serotonin has been proposed to be a mediator of the beta-adrenergic influence on gastric function in vivo, but the counteracting effect of propranolol and the stimulatory effect of serotonin on motility contradict this hypothesis.
D000818:Animals; D001626:Bethanechol Compounds / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D005744:Gastric Acid / Q000378:metabolism*; D005769:Gastrointestinal Motility / Q000187:drug effects*; D007700:Kinetics; D011433:Propranolol / Q000494:pharmacology; D011706:Pyloric Antrum / Q000187:drug effects*; D012636:Secretory Rate / Q000187:drug effects; D012701:Serotonin / Q000494:pharmacology*; D013270:Stomach / Q000502:physiology
D001626:Bethanechol Compounds; D012701:Serotonin; D011433:Propranolol