secretinstimulering

Secretin is a hormone that is released by cells in the stomach and duodenum (the first part of the small intestine) in response to acid chyme entering the duodenum. It is part of the endocrine system and plays a crucial role in digestive processes.

The primary function of secretin is to stimulate the pancreas to secrete bicarbonate ions and water into the duodenum. This alkaline environment is essential for the digestion and absorption of nutrients, particularly fats and proteins. Secretin also inhibits the secretion of gastric acid by the stomach, which helps to protect the intestinal lining from excessive acidity.

The release of secretin is triggered by the presence of acid chyme in the duodenum. This chyme contains hydrochloric acid and pepsin, which are produced by the stomach. The acidity of the chyme signals the duodenal cells to release secretin, which then travels through the bloodstream to the pancreas.

Secretin is a small peptide hormone, consisting of 27 amino acids. It is synthesized and stored in the S cells of the stomach and duodenum. The release of secretin is a classic example of negative feedback regulation, where the presence of a stimulus (acid chyme) inhibits the further release of the hormone.

Secretin is also involved in the regulation of electrolyte balance and the maintenance of fluid and electrolyte homeostasis. Its actions are mediated through the activation of adenylate cyclase in the pancreatic acinar cells, leading to the production of cyclic AMP (cAMP), which then activates protein kinase A (PKA).

Defects in secretin production or action can lead to various digestive disorders, including pancreatic insufficiency and malabsorption syndromes. Therefore, secretin is an important hormone in the complex interplay of hormones and enzymes involved in digestion and nutrient absorption.