What does cholecystokinin mean?
Cholecystokinin (often abbreviated CCK) is a peptide hormone produced by specialised cells in the lining of the duodenum, the first part of the small intestine. Released in response to the presence of fats and proteins arriving from the stomach, it performs several coordinated roles in digestion: it prompts the pancreas to secrete digestive enzymes, causes the gallbladder to contract and discharge bile into the intestine to help emulsify fats, slows gastric emptying, and contributes to the sensation of fullness by acting on the brain as a satiety signal. First identified in the 1920s and later recognised also to function as a neuropeptide in the central nervous system, cholecystokinin remains important in research on appetite regulation and digestive disorders. The term derives from Greek roots meaning 'bile', 'bladder', and 'to move', reflecting its original discovery as the agent that moves the gallbladder.
nounA peptide hormone secreted by the duodenum that stimulates the digestion of fat and protein by triggering the release of digestive enzymes from the pancreas and causing the gallbladder to contract and release bile.
- A peptide hormone produced by I-cells in the duodenal mucosa that stimulates pancreatic enzyme secretion, gallbladder contraction, and satiety.
"The fatty meal triggered a surge of cholecystokinin, prompting the gallbladder to contract and release bile into the small intestine."
"Levels of cholecystokinin rise sharply after a meal rich in fats and proteins."
"Researchers studied how cholecystokinin receptors in the hypothalamus contribute to feelings of satiety."
Rarely pluralised; the hormone is typically discussed as an uncountable substance. Plural forms appear occasionally when referring to variants or related peptide species.
"Different molecular forms of cholecystokinins have been identified in various mammalian tissues."
Cholecystokinin is why a rich, fatty meal makes you feel full — it's the hormone your gut sends to your brain saying 'stop eating.'
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of cholecystokinin
The word cholecystokinin was coined in the early twentieth century from three Greek elements: 'chole' (bile), 'kystis' (bladder), and 'kinin', from Greek 'kinein' (to move). It literally means 'that which moves the gallbladder', describing the hormone's defining action discovered when it was first isolated from intestinal extracts in the late 1920s. It shares its roots with other medical terms built on 'chole-', such as cholecystectomy and cholelithiasis.
How cholecystokinin is actually used
Cholecystokinin is a technical term used almost exclusively in medical, biochemical, and physiological contexts; it is commonly abbreviated as CCK in scientific literature. It is never used colloquially.
Easily confused with cholecystokinin
Secretin is a different gastrointestinal hormone that primarily stimulates pancreatic bicarbonate secretion, whereas cholecystokinin mainly triggers enzyme release from the pancreas and gallbladder contraction.