Cholecystokinin (CCK-8) Novocastra
Cholecystokinin (CCK) was first isolated as a 33 amino acid intestinal peptide hormone that binds saturably and reversibly to distinct receptors in brain and pancreatic cell membranes. In both the brain and intestine, CCK exists in a number of molecular forms of which the C-terminal octapeptide (CCK-8) represents the most abundant molecular species. CCK, gastrin, secretin and vasoactive intestinal polypeptide belong to the gastrointestinal hormone family.
CCK functions to stimulate enzyme secretion from the pancreas, gall bladder contraction, intestinal motility as well as inhibiting gastrin-induced acid secretion. CCK also serves as a neurotransmitter and modulates the action of other neurotransmitters eg dopamine, 5-HT, GABA and excitatory amino acids.
CCK is distributed in several regions of the brain including the cerebral cortex, hippocampus, amygdaloid nuclei and the hypothalamus. CCK is localized mainly in peripheral nerve fibers in the myenteric and submucosal ganglia as well as in endocrine cells of the gastrointestinal tract.