Comparison of the inhibition of histamine- and pentagastrin-stimulated gastric acid secretion by somatostatin in the cat.

The effect of cyclic somatostatin on pentagastrin- and histamine-stimulated gastric acid secretion in conscious cats was studied. Evidence is produced that somatostatin competitively inhibits pentagastrin-stimulated gastric acid secretion whereas it inhibits histamine-stimulated secretion by a mechanism which is not competitive in nature. The vagus nerves seem to be involved in the mode of action of somatostatin as the inhibitory effects are greater in vagotomized than in vagus intact animals.