Secretin

peptide · digestive · IV

Secretin, a peptide. 27-residue peptide secreted by duodenal S-cells in response to gastric acid reaching the duodenum. Activates secretin receptor… IV half-life 0 h.

27-residue peptide secreted by duodenal S-cells in response to gastric acid reaching the duodenum. Activates secretin receptor (Gs-coupled) on pancreatic duct cells → bicarbonate + water secretion; also stimulates biliary duct bicarbonate output and modestly inhibits gastric acid. Used diagnostically: (1) secretin-stimulation test to assess pancreatic exocrine reserve (chronic pancreatitis, cystic fibrosis); (2) gastrinoma stimulation — paradoxical gastrin rise ≥ 110 pg/mL within 10 min confirms Zollinger-Ellison. Very short plasma t½ (~3 min) mandates IV bolus.

PK is CANINE and labelled as such. The previous citation (PMID:755275) is a real human secretin infusion study, but PubMed holds title and authors only — there is NO ABSTRACT — so nothing in it could be verified by this registry's method, and its design (a low-dose steady-state infusion measuring pancreatic response) does not yield a bolus half-life anyway. No human secretin half-life is stated verbatim in any indexed abstract. Replaced by Boden 1974 (PMID:4815082), 3 anaesthetised DOGS on constant IV infusion, verbatim "the half-life of disappearance was 2.8+/-0.1 min" (0.047 h), with a metabolic clearance rate of 730 +/- 34 mL/min and a distribution volume of 17.4% of body weight. An independent PIG estimate gives 2.6 min (PMID:620494) — not averaged, and note the two species' volumes differ about 2.7-fold. The stored 0.067 h matched neither. Also note the usable PK is all for PORCINE secretin while the stored mass is the human peptide.

Pharmacokinetics

Sources: PMID:755275, PMID:4815082, PMID:620494