Gastrin

Abstract

Gastrin is synthesized in the gastric antrum as a large precursor, progastrin. After cleavage and processing, progastrin yields a variety of biologically active peptides including glycine-extended gastrin and the final end product gastrin amide. Gastrin amide acting via the cholecystokinin-2 receptor is the major regulator of meal-stimulated gastric acid secretion, and it also has important roles in epithelial cell proliferation in the gastrointestinal tract. Release of gastrin is stimulated by food, predominantly protein, and inhibited by a low gastric pH. The gastrin peptides, particularly the nonamidated forms, may also be autocrine growth factors in the development of colorectal cancers...