The Effect of Intragastric pH Variations on the Gastric Acid Response to Sham Feeding in Duodenal Ulcer Patients

Abstract

Knutson, U., Bergegârdh, S. & Olbe, L. The effect of intragastric pH variations on the gastric acid response to sham feeding in duodenal ulcer patients. Scand. J. Gastroent. 1974, 9, 357-365.

The gastric secretory response to 15-min sham feeding was determined in duodenal ulcer patients during gastric perfusion with 1/10 M HCl (7 patients), water (10 patients), or 1/15 M Sorensen phosphate buffer, pH 8.0 (3 patients). The antral pH was continuously recorded in 2 patients of each group and was found to be around 1.5, 2.0, and 6.5 respectively. The peak acid response to sham feeding (PAO_sh) amounted to 55% of the peak acid response to pentagastrin (PAOG) during both gastric perfusion with water and alkaline buffer. Gastric perfusion with hydrochloric acid significantly reduced the PAOsh by 49%, owing to reduced volume flow, resulting in a PA0_sh/PAO_G of 33%. The calculated loss of acid gastric contents to the duodenum was equally low during gastric water and acid perfusion (around 0.3 mEq/15 min). Back diffusion of hydrogen ions from the gastric contents during gastric acid perfusion occurred but played a minor role. The results suggest that in the duodenal ulcer patient: 1) acid inhibits the vagal release of gastrin from the antrum at an antral pH below 2, and 2) that the acid secretory rate following physiological vagal activation does not reach the maximal secretory rate following pentagastrin stimulation, despite optimal conditions for vagal release of gastrin.

Key-words::

• Acid inhibition of gastrin release in humans
• cephalic phase of gastric acid secretion
• duodenal ulcer
• vagal release of gastrin