Cholecystokinin Receptor Antibodies

Cholcystokinin receptors are activated by the endogenous peptides cholecystokinin (CCK-8, -33, -58) and gastrin. There are two distinct receptor subtypes now called CCK1 and CCK2 receptors. They were previously classified as Type A (alimentary) and B (brain), respectively, based on their prominent locations. The CCK receptor subtypes are distinguished by their peptide selectivity. CCK1 receptor requires the carboxyl-terminal heptapeptide-amide that includes a sulfated tyrosine for high affinity and potency. CCK2 receptor requires only the carboxyl-terminal tetrapeptide shared by each CCK and gastrin peptides. The physiological roles for CCK relate to nutritional homeostasis, with activities to stimulate gallbladder contraction, pancreatic exocrine secretion, gastric emptying, intestinal transit, and satiety. The major physiological role for gastrin is the stimulation of gastric acid secretion. Agonist stimulation normally leads to stimulation of phospholipase C and increases in intracellular calcium by coupling to Gq proteins.  Potential therapeutic areas being considered for CCK antagonists include anxiety, nociception, appetite control, depression, learning, memory, neuroprotection, drug dependence, and gastrointestinal dysmotility states. None of these agents are currently approved for standard clinical use.