Effects of antral acidification and atropine on histamine-induced gastric secretion in dogs

Abstract

To determine whether acid in the gastric antrum causes inhibition of HCl secretion in the fundus of the stomach, five dogs were prepared with antral and fundic pouches. In one animal these pouches had intact vagal innervation. In each experiment a small dose of histamine was administered at a constant rate for 5–6 hours. After the rate of HCl output from the fundic pouch leveled off, the antral pouch was perfused with acid for 3 hours. During this period the rate of HCl output sometimes fell below preperfusion level, but similar results were obtained without antral perfusion. The findings in 30 tests and 30 controls failed to suggest that antral acidification influenced the fundic secretion. In a parallel study, 2 mg of atropine produced marked inhibition of secretion, proving that true inhibitory effects were demonstrable with the methods employed. These findings raise doubt that the acidified antrum produces an antisecretory hormone or that it can inhibit fundic secretion via a vagal reflex.