Gastrin Releasing Peptide
- OMIM: 137 260
- MGI: 95833
Gastrin releasing peptide (GRP) or 148 polypeptide is one of several factors that promote the release of gastrin. This leads to a significant increase in the production of hydrochloric acid in the stomach. Is a polypeptide having 27 amino acids, which is one of bombesin, and litorin Neuromedin B, all of which act as specific agonists for the family of bombesinähnlichen peptides.
Primary structure
Primary structure: H2N - Val-Pro -Leu- Pro-Ala -Gly-Gly -Gly- Thr -Val -Leu- Thr -Lys -Met -Tyr -Pro-Arg -Gly -Asn -His -Trp -Ala- Val -Gly -His -Leu -Met- CONH2.
Case 9 of the last 10 amino acids at the C -terminus are identical to those of bombesin. Specific agonists of GRP are the polypeptides bombesin, neuromedin B and Litorin.
Education center
GRP is formed by neuroendocrine cells of the stomach ( antrum ), and the duodenum and pituicytes of the central nervous system, these cells were also detected in time between the lungs of infants and adults. Patients with chronic lung disease have an increased GRP -forming cells in the respiratory tract without affecting their function would be clarified so far.
Effect
GRP increases gastrin in the G- cells of the stomach and thus the formation of gastric acid. Further the neuropeptide results in an increase of pancreatic enzyme secretion. At the smooth muscle of the stomach and gallbladder particularly GRP leads to contraction, so that a rapid gastric emptying. In addition to other substances ( bombesin, cholecystokinin ) and GRP promotes the occurrence of satiety.
Oncology
Small cell lung carcinoma produced (SCLC for Small Cell Lung Cancer ) as a neuroendocrine tumor next to neurotensin (NT) and adrenomedullin (AM) and GRP as autocrine growth factors. GRP is also demonstrated in medullary thyroid carcinoma, carcinoid, metastatic islet cell carcinoma increased.