Gastric inhibitory polypeptide (GIP)
GIP, a member of the glucagon family, is derived from a 153aa proprotein encoded by the GIP gene and circulates as a biologically active 42aa peptide hormone. Synthesized by K-cells and found in the mucosa of the duodenum and jejunum of the GI tract, GIP is transported by blood and affects fatty acid metabolism. Once released into the blood, GIP is quickly broken down and inactivated. It is believed GIP's major function is to induce insulin secretion. The amount of insulin secreted is greater when glucose is administered orally rather than IV. Type 2 Diabetics are not responsive to GIP and have lower levels of GIP secretion following a meal than non-Diabetics.
Swiss-Prot Accession Number: P09681