Human GIPR Gastric Inhibitory Polypeptide Receptor-expressing GPCR (G protein-coupled receptor) division-arrested cells. Gastric inhibitory polypeptide (GIP) is a 42-amino acid polypeptide synthesized by K-cells of the duodenum and small intestine. GIP’s principle physiological action is to stimulate insulin secretion from pancreatic β-cells in a glucose-dependent manner. Additional effects of GIP have been described, including effects on lipid metabolism, stimulation of glucagons and somatostatin release. GIP exerts its effects by binding to its specific receptor, the GIP receptor which belongs to the VIP/glucagon/secretin family of G protein-coupled receptors and is positively coupled to adenylyl cyclase but not to phospholipase C. Learn More