Regulation of gastrin and gastric acid secretion

Gastrin is released from the antrum of the stomach when gastric acid is reduced. Circulating gastrin binds to ECLs, which lie near parietal cells and release histamine, which stimulates acid secretion. Although parietal cells possess receptors for gastrin, ACh, histamine, and somatostatin, the major effects of gastrin on acid secretion are mediated by ECL histamine.