The effects of antral acidification on the gastric secretion stimulated by endogenous and exogenous gastrin

Abstract

SUMMARY1. In conscious dogs with Heidenhain fundic pouches and denervated antral pouches control dose-response curves to gastrin pentapeptide or methacholine were constructed, both when the antral pouch was empty and when it was stimulated with ACh (0.5 g/100 ml.) in citrate buffer adjusted to pH 5-5 or 1-5.2. When the antral pouches were irrigated with ACh (0.5 g/100 ml.) at pH 1-5 the acid outputs from the Heidenhain pouch in response to graded doses of gastrin pentapeptide or methacholine were significantly less at each dose level than those obtained with ACh at pH 5-5. 3. The acid outputs from the Heidenhain pouch in response to either pentapeptide or methacholine with or without antral irrigation with ACh at pH 1-5 were approximately equal. Therefore the difference between the dose-response curves obtained by stimulation with ACh at pH 5*5 and those obtained by stimulation with ACh at pH 1-5 represents gastrin release rather than release of an inhibitory hormone.4. The pepsin outputs from the Heidenhain pouch during antral irrigation with ACh at pH 1*5 were significantly less than those obtained with ACh at pH 5-5 at each dose of methacholine.o. The maximal pepsin output was significantly greater in response to methacholine than to gastrin pentapeptide.6. Gastrin pentapeptide was not a significant stimulant of pepsin secretion from the Heidenhain pouch.7. The intestinal phase of parietal secretion was not inhibited by bathing the separated antrum with acid.

Cyclic changes of plasma pancreatic polypeptide and pancreatic secretion in fasting dogs.

“…Gastric secretion was collected by simple drainage, pouch secretion by the saline wash-out method (Magee & Nakajima, 1966) and pancreatic secretion by direct cannulation of the duct through the Thomas fistula. Motility of the stomach and the duodenum were recorded by small rubber balloons introduced through the gastric and the duodenal fistulae.…”

Relationship Between Serum Gastrin Levels and Gastric Secretion in Heidenhain Pouch Dogs

“…The first explanation is favoured since there is a more dense cholinergic innervation in the parietal than in the antral region (14). Secretory stimulation in fasting dogs soon results in antral acidification which has been postulated to inhibit gastrin but not parietal cells (15). En dogenous gastrin release by bethanecol and tetramethylammonium is no doubt inhibited by antral acidification.…”

Comparison of the action of cholinomimetics and pentagastrin on gastric secretion in dogs

“…Gastric fistula secretion was collected by simple drainage and the pouch secretion by the washout method of Magee & Nakajima (1968). All secretions were collected continuously and were measured and sampled at 10 min intervals.…”