Human Hormones

Glucose-dependent insulinotropic peptide (GIP), formerly known as gastric inhibitory peptide, is a hormone found in the human body. It is secreted by the K-cells in the duodenum of the gastrointestinal tract. GIP is classified as a peptide hormone.
Secretion and Production

GIP is derived from a 153-amino acid proprotein encoded by the GIP gene and circulates as a biologically active 42-amino acid peptide. GIP is synthesized by enteroendocrine K-cells whose locations are primarily in the duodenum and proximal jejunum. The original activity associated with GIP was the inhibition of gastric acid secretion and was thus, originally called gastric inhibitory peptide. However, subsequent research demonstrated that this gut hormone possessed potent stimulation of glucose-dependent insulin secretion. In addition, GIP has significant effects on fat metabolism exerted at the level of adipocytes.
Pharmacological Uses

Synthetic GIP is currently being researched for its potential use in treating diabetes. It has been found that diabetics have a loss of GIP secretion and production; therefore, synthetic GIP could be of use by stimulating insulin secretion.