Antral acidification and the gastric secretory response to pentagastrin and acetylcholine in dogs.

In 6 dogs with innervated antral pouches (3 with vagally innervated fundic pouches and 3 with vagally denervated fundic pouches) gastric secretion was stimulated by a range of submaximal doses of pentagastrin, each infused intravenously for a period of 6 hours. During the three consecutive 2-hour collection periods of each test the antral pouch was perfused with isotonic saline of pH 7 0, 1.0 and 7.0 respectively at a rate of I ml/min. Neither acid nor pepsin secretion was inhibited by antral acidification. When the antral perfusion rate was increased to 3 ml/min there was still no inhibition of acid secretion from either type of fundic pouch. In each dog the acid response of the fundic pouch to perfusion of the innervated antral pouch with 0–5 per cent acetylcholine was significantly reduced when the pH of the perfusate was lowered from 7.0 to 1.0. The results provide no support for the existence of either an antral inhibitory hormone or inhibitory neural reflex active against pentagastrin-stimulated gastric secretion in the dog. It would seem that antral inhibition of gastric secretion is the result of a diminished release or formation of endogenous gastrin.