Gastric inhibitory polypeptide

Gastric Inhibitory Polypeptide (GIP), also known as glucose-dependent insulinotropic polypeptide, is a hormone that is secreted from the K cells in the duodenum and the jejunum of the small intestine. It is involved in several metabolic processes, including the stimulation of insulin secretion from the pancreas.

Function

GIP is released in response to the ingestion of nutrients, including fats, carbohydrates, and proteins. It acts on the beta cells of the pancreas to enhance the secretion of insulin, a hormone that regulates blood glucose levels. This effect is glucose-dependent, meaning it only occurs when blood glucose levels are elevated.

In addition to its insulinotropic effects, GIP also has several other functions. It inhibits gastric acid secretion, hence its name "gastric inhibitory polypeptide". It also promotes the growth and survival of the beta cells in the pancreas, and it may play a role in lipid metabolism by promoting the storage of fat in adipose tissue.

Clinical significance

Alterations in GIP function have been implicated in several diseases, including type 2 diabetes and obesity. In type 2 diabetes, the insulinotropic effect of GIP is impaired, a condition known as GIP resistance. This contributes to the hyperglycemia that characterizes this disease.

In obesity, GIP may promote the storage of fat in adipose tissue, contributing to weight gain and the development of obesity-related complications. However, the exact role of GIP in obesity is still under investigation.

See also

• Insulin
• Glucagon-like peptide-1
• Incretin
• Type 2 diabetes
• Obesity