Important stimulants of gastrin release from endocrine cells in the antrum include:

b. Small peptide fragments and amino acids from luminal proteolysis

Gastrin is processed to 34-and 17-amino acid forms in endocrine cells in the gastric antrum. In addition to well-recognized stimulatory actions on gastric acid secretion, gastrin promotes mucosal growth of the gastric fundus and small intestine. The most important stimulant of gastrin release is a meal. Small peptide fragments and amino acids that result from intragastric proteolysis are the food components that stimulate gastrin release. Ingested fats and carbohydrates have no significant effect. In this regard, intraluminal pH strongly affects gastrin secretion. If intragastric pH is maintained above 3 after ingestion of a meal, gastrin release is strongly potentiated. Pernicious anemia and atrophic gastritis, which produce chronic achlorhydria, are associated with fasting hypergastrinemia and an exaggerated gastrin meal response. Conversely, antral acidification strongly inhibits gastrin secretion. Locally-released somatostatin mediates the effects of luminal acidification, inhibiting gastrin secretion.