Secretin: Endogenous Peptide Hormone Reference
27-amino acid gut hormone that stimulates pancreatic bicarbonate secretion and regulates gastric acid output. This peptide or oligopeptide is studied for its...
Chemical Identity
| Property | Value |
|---|---|
| Chemical Formula | C130H220N44O40 |
| Molecular Weight | 3055 Da |
| CAS Number | 1393-25-5 |
| Peptide Class | Gut Hormone (27 amino acids) |
| Sequence | HSDGTFTSELSRLREGARLQRLLQGLV-NH2 |
Structure
Secretin is a 27-amino acid linear peptide hormone and the first hormone to be discovered (1902). It belongs to the secretin-glucagon-VIP family, sharing structural homology with these peptides. The C-terminal amide is essential for receptor binding.
Mechanism of Action
Secretin binds secretin receptors on pancreatic ductal cells, activating adenylyl cyclase and increasing cAMP. This stimulates copious bicarbonate-rich fluid secretion that neutralizes gastric acid entering the duodenum. Secretin also stimulates bile flow and inhibits gastric acid secretion.
Clinical Applications
- Pancreatic function testing: Secretin stimulation test for exocrine insufficiency
- Gastrinoma diagnosis: Secretin provocative test
- Autism: Investigational (IV secretin for GI symptoms)
- Gastric acid regulation: Endogenous acid neutralization
Pharmacology
- Half-life: 3-5 minutes
- Release: S-cells (duodenum) in response to acid (pH <4.5)
- Target: Pancreatic ductal cells
- Analogs: Not widely used clinically
References
- Bayliss, W.M., & Starling, E.H. (1902). The mechanism of pancreatic secretion. Journal of Physiology, 28, 325-353.
- Chey, W.Y., & Chang, T.M. (2003). Secretin: a century of discovery. Pancreas, 26, 327-332.
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