Glucagon is a 29 amino acid polypeptide synthesized and secreted from alpha cells of the islets of Langerhans in the pancreas. Glucagon is involved in carbohydrate metabolism. It is released during hypoglycemia, causing the liver to convert stored glycogen into glucose and release it into the bloodstream. Glucagon secretion is increased due to a decrease in plasma glucose, an increase in catecholamine, an increase in plasma amino acids, sympathetic nervous system, acetylcholine, and cholecystokinin. Glucagon secretion is inhibited by insulin and somatostatin.
Swiss-Prot Accession Number: P01275