Cholecystokinin (CCK)
Also known as: CCK, Pancreozymin, CCK-8, CCK-33
Overview
Cholecystokinin (CCK) is a peptide hormone found in multiple forms (CCK-8, CCK-33, CCK-58) secreted by enteroendocrine I-cells of the duodenum and jejunum in response to dietary fat and protein. It is among the most important physiological satiety signals, acting centrally via vagal afferents to terminate meals and promote satiety. CCK also stimulates gallbladder contraction and pancreatic enzyme secretion, facilitating fat and protein digestion. In the CNS, CCK acts as a neuromodulator influencing anxiety, analgesia, and memory formation.
Mechanism of Action
CCK binds two GPCRs: CCK-1R (expressed in vagal afferents, gallbladder, pancreas, enteric neurons) and CCK-2R (expressed in CNS, stomach). CCK-1R activation via Gq/11 stimulates inositol phospholipid turnover and intracellular calcium release. In the GI tract, this causes gallbladder contraction, pancreatic acinar cell exocytosis of digestive enzymes, and Oddi sphincter relaxation. Vagal CCK-1R activation transmits satiety signals to nucleus tractus solitarius and hypothalamic POMC neurons. The CNS CCK-2R mediates anxiety-like responses, analgesia modulation, and dopaminergic/opioidergic interactions.
Potential Benefits
- Physiological satiety signaling and meal termination
- Pancreatic enzyme secretion stimulation for fat/protein digestion
- Gallbladder contraction promoting bile flow
- CNS neuromodulation (anxiety, memory, analgesia)
- Research target for anti-obesity drug development (CCK-1R agonists)
Research Dosage Notes
The following reflects doses used in published research studies. This is not medical advice.
Research context primarily. CCK-1R agonists in clinical trials for obesity at investigational doses.
Amino Acid Sequence
Asp-Tyr(SO3H)-Met-Gly-Trp-Met-Asp-Phe-NH2 (CCK-8 sulfated; biologically active form)
Side Effects & Safety
- Nausea at pharmacological doses
- Abdominal cramps
- CNS anxiety-like effects via CCK-2R
Synergistic Compounds
The following compounds have been studied alongside Cholecystokinin (CCK) for potential complementary or synergistic effects:
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References & Further Reading
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