Serum secretin

Secretin is a gastrointestinal hormone (also known as secretin, secretin) released by duodenal mucosal S cells and S cells dispersed in the jejunum (mainly the upper end). Secretin is an alkaline The peptide, consisting of 27 amino acids, has 9, 9, and 14 amino acid sequences that are identical to the amino acid sequences of gastric inhibitory peptide, vasoactive intestinal peptide, and glucagon, respectively. It is suggested that they evolved from the same hormonal ancestor, so these four peptides are classified into one family, called the secretin family. Secretin is mainly eliminated by the kidneys. Gastric acid is the main physiologically strongest factor that stimulates the release of pancreatin. The pH threshold for stimulating its release is 4.5. Others such as bile, sodium bile and fat, calcium ions, and alcohol all stimulate the increase of pancreatin. Secretin has the following physiological effects: ① Strongly stimulate pancreas exocrine glands to secrete water and sodium bicarbonate. ② stimulate bile secretion. ③Inhibit gastrin release and gastric acid secretion, and inhibit local release of somatostatin. ④ Inhibit gastrointestinal peristalsis, delay the emptying of gastric juice and solid food, and enhance the gallbladder contraction of cholecystokinin.