Role of adrenergic agonists on gastric secretion in the rat.

Abstract

Following previous demonstration that isoproterenol stimulated and norepinephrine inhibited gastric acid secretion induced by secretagogs, role of adrenergic agonists was studied by measuring acidity and peptic activity of the effluent of the perfused rat stomach. Response of gastric secretion to isoproterenol was increased by theophylline but was not affected by metiamide. Dibutyryl-cAMP stimulated gastric secretion in a dose-dependent manner. The action of isoproterenol in gastric acid secretion may be mediated by cAMP. Gastric secretion induced by pentagastrin, histamine or carbamylcholine was not affected by theophylline treatment. Dibutyryl-cGMP did not exert any effect on gastric secretion. Depression of pentagastrin-induced gastric secretion by norepinephrine was reversed by EGTA [ethylene glycol bis(.beta.-aminoethyl ether) N,N,N''-tetraacetic acid] infusion. Ca2+ depressed pentagastrin-induced gastric secretion. The action of norepinephrine is closely related to the concentration of Ca2+.