Cholecystokinin Pancreozymin C Terminal Octapeptide, commonly referred to as CCK-8, is a bioactive peptide hormone composed of eight amino acids. It is a naturally occurring peptide found in the gastrointestinal tract and the central nervous system, primarily in the brain and the small intestines.
CCK-8 is derived from the larger precursor peptide, cholecystokinin pancreozymin, through enzymatic cleavage. It acts as a neurotransmitter in the brain and as a hormone in the digestive system. Upon release, CCK-8 interacts with two distinct receptor subtypes, CCK-A and CCK-B.
In the central nervous system, CCK-8 functions as a neuropeptide and is involved in various physiological processes, including the regulation of appetite, anxiety, mood, and pain perception. It has been implicated in the modulation of feeding behavior, as it is released in response to the presence of food in the digestive system, leading to satiety signals and the suppression of appetite.
In the gastrointestinal tract, CCK-8 is released by the endocrine cells in the duodenum in response to the presence of fats and proteins. It acts on the gallbladder to induce the release of bile, promoting the digestion and absorption of dietary fats. Moreover, CCK-8 stimulates the secretion of digestive enzymes from the pancreas, facilitating the breakdown of food components.
Overall, CCK-8 is a crucial peptide hormone that plays a pivotal role in the regulation of appetite, digestion, and various physiological processes in both the central nervous system and the gastrointestinal tract.
