Exogenous serotonin and histamine-stimulated gastric acid and pepsin secretion in dogs.
The effects of serotonin on histamine-stimulated gastric acid and pepsin secretion were evaluated in conscious dogs with a gastric fistula. Histamine stimulated the acid secretion dose-dependently, whereas pepsin secretion was decreased by the high doses of histamine. The acid secretion was inhibited slightly by serotonin, with a maximum of 42% with a dose of 10 micrograms/kg/min. The pepsin secretion was only decreased non-significantly by serotonin, 10-15 micrograms/kg/min. The acid inhibition was counteracted by beta-adrenergic antagonists (propranolol, atenolol) and methysergide (serotonergic antagonist). The dose-response analysis showed inhibition of a competitive type. In conclusion, serotonin inhibits histamine-stimulated gastric acid secretion via serotonergic receptors and beta-adrenoceptors, whereas pepsin secretion is unaffected.
D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000818:Animals; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D005744:Gastric Acid / Q000378:metabolism*; D006632:Histamine / Q000494:pharmacology*; D008784:Methysergide / Q000494:pharmacology; D010434:Pepsin A / Q000378:metabolism*; D012701:Serotonin / Q000494:pharmacology*
D000319:Adrenergic beta-Antagonists; D012701:Serotonin; D006632:Histamine; D010434:Pepsin A; D008784:Methysergide