Cholecystokinin (CCK)

Cholecystokinin (CCK) is a peptide hormone produced by I-cells in the mucosal lining of the upper small intestine (duodenum and jejunum) and also by certain neurons in the brain. Its secretion is stimulated primarily by the presence of fats and proteins in the intestinal lumen. Upon release, CCK acts on its receptors (mainly cholecystokinin receptor 1, CCK1R) on the pancreas and gallbladder to stimulate the release of digestive enzymes and bile. It also slows gastric emptying, increases intestinal motility, and triggers signals of satiety to the brain. CCK also functions as a neuropeptide, influencing behavior and central nervous system signaling. The release mechanism is tightly regulated via nutrient sensing and neurohumoral pathways.

Other names

Pancreozymin (historical)CCK

Drugs that mimic CCK stimulate gallbladder contraction and pancreatic secretion. CCK receptor antagonists block these processes and reduce GI motility or secretion.