Effect of somatostatin on bethanechol-stimulated gastric pepsin secretion in gastric fistula dogs.

The effect of somatostatin on pepsin secretion was determined in six dogs with gastric fistulas during stimulation with bethanechol. Somatostatin inhibited dose-dependently the stimulated pepsin secretion, with a dose of 0.3 micrograms/kg/h being 35% inhibitory during stimulation with bethanechol, 80 micrograms/kg/h. Continuous infusion of somatostatin for 3 h did not cause any signs of tachyphylaxis. Withdrawal of somatostatin produced a return to the control level. The dose-response kinetics with five doses of bethanechol with and without somatostatin showed inhibition of a noncompetitive type. The effects of somatostatin were not altered by using adrenergic, dopaminergic, or serotonergic blocking drugs.