Gastrin stimulates the stomach mucosa to produce and secrete hydrochloric acid and the pancreas to secrete its digestive enzymes. It also stimulates smooth muscle contraction and increases blood circulation and water secretion in the stomach and intestine. Sulfation enhances proteolytic processing, and blocks peptide degradation. Levels of sulfation differ between proteolytically-cleaved gastrins. Thus, gastrin-6 is almost 73% sulfated, whereas the larger gastrins are less than 50% sulfated. Sulfation levels are also tissue-specific. Belongs to the gastrin/cholecystokinin family.