Gastrin
| Gastrin | ||
|---|---|---|
| Properties of human protein | ||
| Mass / length primary structure | 6/14/17/34/53/71 amino acids | |
| Secondary to quaternary structure | Protein sulfate | |
| Precursor | (101 aa; 11.4 kDa) | |
| Identifier | ||
| Gene names | GUEST ; GAS | |
| External IDs | ||
| Occurrence | ||
| Parent taxon | Higher mammals | |
| Orthologue | ||
| human | mouse | |
| Entrez | 2520 | 14459 |
| Ensemble | ENSG00000184502 | ENSMUSG00000017165 |
| UniProt | P01350 | Q6GSF5 |
| Refseq (mRNA) | NM_000805 | NM_010257 |
| Refseq (protein) | NP_000796 | NP_034387 |
| Gene locus | Chr 17: 37.12 - 37.13 Mb | Chr 11: 100.15 - 100.15 Mb |
| PubMed search | 2520 |
14459
|
Gastrin or polypeptide 101 (PP 101) is a peptide hormone of the gastrointestinal tract and exerts - in addition to other effects such. B. the increase in cardiac sphincter tone - the strongest stimulus for the production of gastric acid .
Structurally, it is closely related to cholecystokinin . The gastrin is formed in the G cells in the antrum pyloricum of the stomach and in the duodenum and transported from there via blood vessels to its sites of action. Increased gastrin production by a hormone-producing tumor , a so-called gastrinoma , can rarely occur.
The synthesis was achieved in the 1960s by George Wallace Kenner .
to form
The three forms of gastrin differ in the length of their peptide chain:
| Gastrin form | Length of the peptide chain |
|---|---|
| Big gastrin | 34 amino acids |
| Gastrin I and II | 17 amino acids |
| Mini-gastrin also gastrin (5-17) |
14 amino acids |
Control of the delivery
The secretion (discharge) of gastrin is stimulated by:
- the stretching of the stomach (especially from eating)
- Proteins and peptides in food
- Irritation of the vagus nerve and the subsequent release of GRP (gastrin releasing peptide) and acetylcholine (thus also through the consumption of nicotine )
- Alcohol consumption , caffeine , not due to other methyl xanthine
The secretion is inhibited by:
- pH below 3
- VIP (vasoactive intestinal peptide)
- Somatostatin
- Secretin
- GIP (Gastrin Inhibiting Peptide)
- Neurotensin
effect
Gastrin mainly affects the stomach. It stimulates:
- the smooth muscles of the stomach,
- the production of pepsinogen (protein breakdown protein precursor) in the main cells of the stomach,
- the hydrochloric acid production of the parietal cells (activation of PLCβ) and
- the histamine production (tissue hormone, here for hydrochloric acid production stimulation) of the so-called ECL cell (enterochromaffine-like cell) .
Gastrin also has an effect on the pancreas, where it stimulates the release of insulin (blood sugar lowering agent ), glucagon (blood sugar increasing agent ) and somatostatin (gastrin and pepsin inhibitor).
Decoupled effect
When Zollinger-Ellison syndrome is multiple neuroendocrine tumors (NET) , which then is most common in the pancreas , the small intestine or the liver find autonomously produce gastrin. The normally closed control loop is broken by the permanent flooding of the gastrin in the blood.
In the stomach, the parietal cells react to the unphysiologically increased gastrin level with hyperplasia and produce more hydrochloric acid . This in turn can lead to further damage to the lining of the stomach and small intestine .
Individual evidence
- ↑ UniProt P01350 .
- ↑ SE Miederer et al .: Gastrin release by methylxanthine , Klin. Wschr. 51 (1973) 42.
- ↑ E Ipp, RE Dobbs, V Harris, A Arimura, W Vale, RH Unger: The effects of gastrin, gastric inhibitory polypeptide, secretin, and the octapeptide of cholecystokinin upon immunoreactive somatostatin release by the perfused canine pancreas. . In: Journal of Clinical Investigation . 60, No. 5, November 1977, pp. 1216-1219. PMC 372476 (free full text).
