Three stimuli (neurologic, physical, and hormonal) trigger the parietal cell to secrete acid.

Regulation of Gastric Acid Secretion-screen-shot-2015-10-13-at-8-50-41-pm-png

  • Neurologic impulses, from the central nervous system and initiated by the sight, smell, and taste of food, travel along cholinergic pathways to stimulate the release of acetylcholine, which arrives via nerve endings and activates the muscarinic receptor on the parietal cell.
  • Ingested food causes gastric dissension, which triggers the release of acetylcholine and also stimulates G cells within the antrum to produce gastrin.
  • Elevated intragastric pH also stimulates the production of gastrin.
  • The stomach is protected from overproduction of gastric acid by the release of somatostatin from antral D cells, which signal the G cell to stop the production of gastrin.
  • Gastrin enters the blood and arrives at the parietal cell, where it binds to the gastrin receptor.
  • Acetylcholine and gastrin promote the release of histamine from the mast cells or enterochromaffinlike (ECL) cells, which then bind to the histamine H2 receptor on the parietal cell.
  • Histamine release is associated with both postprandial and nocturnal acid secretion.