Inhibition of pentagastrin-stimulated gastric acid secretion by acid perfusion of the duodenum in chronic gastric fistula rats.

The effect of duodenal acid perfusion on pentagastrin-stimulated gastric acid secretion was studied in Sprague-Dawley rats provided with a chronic gastric fistula, gastroenterostomy, and a 4-cm blind duodenal loop anastomosed to the jejunum. During maximal acid stimulation with intravenous pentagastrin (16 micrograms X kg-1 h-1) the loop was perfused with 0.15 M NaCl or 0.05 M, 0.10 M, or 0.20 M HCl at a rate of 2 ml X h-1. Perfusion with 0.05 M HCl did not significantly alter pentagastrin-stimulated secretion. 0.10 M and 0.20 M HCl reduced the 2-h acid response by 56% and 63%, respectively. Acid secretion returned to control level after cessation of acid perfusion. It is concluded that physiological amounts of HCl in the duodenum inhibits maximal acid secretion stimulated by pentagastrin in rats.