Description
Glucagon is a 29-residue polypeptide hormone (MW 3482), produced in the pancreas. A related hormone, enteroglucagon (or oxyntomodulin), which is produced in the mucosa of the small and large intestine, consists of the 29 amino acid sequence of pancreatic glucagon extended by 8 additional residues at the C-terminus. The biological activities of pancreatic glucagon include glycogenolysis, lipolysis, gluconeogenesis, and ketogensis, which are antagonistic effects to those of insulin action, thus leading to increased blood glucose levels. Immunocytochemical studies have revealed the presence of pancreatic glucagon inside the A or alpha cells, which constitute 15-20% of the islet cell population. These cells are located preferentially at the periphery of the human pancreatic islets. Pathological manifestations of the glucagon-type peptide residue almost exclusively with the exsistence of tumors or glucagonomas, as no states of glucagon-cell deficiency or hyperplasia have been identified. Glucagon-specific antibodies would prove useful as a cell and tumor markers applying immunohistochemical techniques, and as an analytical tool in qualification of the hormone