<protein> A group of peptide hormones secreted by the mucosal gut lining of some mammals in response to mechanical stress or high pH. When there is food in the stomach, these cells secrete gastrin.

Gastrin then stimulates the stomach parietal cells to produce hydrochloric acid. Normally, as stomach pH lowers, gastrin secretion decreases. Gastrin blood levels can be determined to be elevated in conditions such as Zollinger-Ellison syndrome and pernicious anaemia.

Several different gastrins have been identified, human gastrin I has 16 amino acids (2116 D). Gastrin is competitively inhibited by cholecystokinin.

(05 Jan 1998)