CCK is an endocrine hormone

Cholecystokinin

Synonym: Cholecystokinin (CCK), Pankreozymin (PZ)
English: cholecystokinin

1 definition

Cholecystokinin is a peptide hormone secreted by endocrine cells (I cells) of the duodenum and jejunum.

2 function

Cholecystokinin, by binding to CCK receptors, stimulates the secretion of enzymes from the pancreas and causes the gallbladder to contract. Due to the higher affinity of the CCK to the CCKb-Receptors of the stomach, it displaces gastrin from these and ensures a reduction in the secretion of hydrochloric acid by the parietal cells.

In addition, cholecystokinin binds to CCK receptors, which are expressed in the brain (CCK1 receptor and CCK2 receptor) and in the vagus nerve (CCK1 receptor). CCK imparts a physiological feeling of satiety in the CNS and thereby reduces the intake of food and calories. CCK also inhibits gastric emptying.

Blocking the CCK1 receptors leads to a 9% increase in food or energy consumption in healthy test subjects.

3 secretion

Cholecystokinin is secreted from the enteroendocrine cells of the duodenum or jejunum during and after ingestion. The strongest secretion stimulus are free fatty acids, which arise from the hydrolysis of triglycerides in food and come into contact with the enteroendocrine cells. The length of the free fatty acids plays an essential role. CCK secretion is only triggered by fatty acids with a minimum length of 12 carbon atoms. If shorter fatty acids are administered or orlistat is administered, which inhibits fatty acid absorption with medication, there is no CCK secretion.

The contact of the fatty acids with the enteroendocrine cells of the duodenum and jejunum is obligatory. Intravenous administration of fatty acids does not induce CCK secretion.