Gastric acid secretion and its regulation
How parietal cells make acid, how acetylcholine, gastrin, histamine and somatostatin control it, where acid-suppressing drugs act, and how this explains hypergastrinaemia, Zollinger-Ellison syndrome, achlorhydria and vomiting alkalosis.
Tier 1Medical sciences concept
Written with AI assistance and fact-checked against the sources below. For exam study, not clinical decisions. How notes are made
At a glance
- The stomach secretes 1.5 to 2.5 L a day at a pH of about 1 (secreted acid near 150 mmol/L H+), against a plasma H+ of 40 nmol/L: a gradient of about 3 million-fold, driven by the H+/K+-ATPase.
- Parietal cells in the fundus and body make acid and intrinsic factor. Antral G cells make gastrin. ECL cells release histamine. D cells release somatostatin.
- Three stimuli: acetylcholine, gastrin, histamine. Main brake: somatostatin.
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Sources
- Control of gastric acid secretion in health and diseaseGastroenterology (Schubert and Peura, 2008;134:1842-1860), 2008
- Diagnosis of Zollinger-Ellison syndrome in the era of PPIs, faulty gastrin assays, sensitive imaging and limited access to acid secretory testingInternational Journal of Endocrine Oncology (Metz, Cadiot, Poitras, Ito and Jensen, 2017;4:167-185), 2017
- Serum gastrin in Zollinger-Ellison syndrome: I. Prospective study of fasting serum gastrin in 309 patients from the National Institutes of Health and comparison with 2229 cases from the literatureMedicine (Baltimore) (Berna, Hoffmann, Serrano and Jensen, 2006;85:295-330), 2006
- Sleisenger and Fordtran's Gastrointestinal and Liver Disease (11th ed.)Elsevier (Feldman, Friedman and Brandt, 2021), 2021
- Guyton and Hall Textbook of Medical Physiology (14th ed.)Elsevier (Hall and Hall, 2021), 2021
- Last updated
- 14 November 2026
What changed
- 14 November 2026 Personal emails, About story and Australian-style copy