Gastrin and gastric epithelial physiology

Transepithelial transducing cells, particularly the gastrin (G) cell, co-or dinate gastric acid secretion with the arrival of food in the stomach. Rece nt work suggests that multiple active products are generated from the gastr in precursor, and that there are multiple control points in gastrin biosynt hesis. Biosynthetic precursors and intermediates (progastrin and Gly gastri ns) are putative growth factors; their products, the amidated gastrins, reg ulate epithelial cell proliferation, the differentiation of acid-producing parietal cells and histamine-secreting enterochromaffin-like (ECL) cells, a nd the expression of genes associated with histamine synthesis and storage in ECL cells, as well as acutely stimulating acid secretion. Gastrin also s timulates the production of members of the epidermal growth factor (EGF) fa mily, which in turn inhibit parietal cell function but stimulate the growth of surface epithelial cells. Plasma gastrin concentrations are elevated in subjects with Helicobacter pylori, who are known to have increased risk of duodenal ulcer disease and gastric cancer. Studies of the physiology of ga strin may therefore contribute to an understanding of the mechanisms releva nt to major upper gastrointestinal tract disease.