kolekystokiini

Kolekystokiini, often abbreviated as CCK, is a peptide hormone primarily produced by enteroendocrine cells in the duodenum and jejunum, the upper parts of the small intestine. Its release is stimulated by the presence of fats and proteins in the chyme that enters the small intestine from the stomach.

The main functions of CCK are to regulate digestion and promote satiety. It acts on several targets within the digestive system. CCK stimulates the contraction of the gallbladder, leading to the release of bile into the small intestine, which aids in the emulsification and absorption of dietary fats. It also promotes the secretion of pancreatic enzymes from the pancreas, which are crucial for breaking down fats, proteins, and carbohydrates into smaller molecules that can be absorbed. Furthermore, CCK inhibits gastric emptying, slowing down the rate at which food leaves the stomach, thus allowing more time for digestion and absorption in the small intestine.

Beyond its digestive roles, CCK also plays a significant part in the regulation of appetite and satiety. It acts on receptors in the brain, particularly in the hypothalamus and brainstem, to signal fullness to the body. This contributes to the feeling of being satisfied after a meal and can reduce subsequent food intake. CCK is also found in the brain, where it is thought to have roles in neurotransmission and other neurological functions.