Peptide Database

CCK · CCK-8

Cholecystokinin (CCK) is a peptide hormone produced by duodenal I-cells and neurons in the CNS. It triggers gallbladder contraction, pancreatic enzyme secretion, and potently suppresses appetite via vagal nerve CCK1 receptors. In the brain, CCK neurons modulate anxiety, pain, memory consolidation, and dopamine release. CCK antagonists are studied for anxiety and pain; CCK agonists for obesity and eating disorders.

GAL

Galanin is a 29-30 amino acid neuropeptide widely distributed throughout the CNS and peripheral nervous system. It modulates memory, mood, pain, seizures, appetite, and sleep via three receptor subtypes (GALR1–3). Research focuses on its roles in Alzheimer's disease (galanin hyperinnervation of cholinergic neurons), depression, epilepsy, and eating behavior. Both agonists and antagonists have therapeutic potential depending on the target condition.

Glucose-dependent Insulinotropic Polypeptide · Gastric Inhibitory Polypeptide

GIP is a 42-amino-acid incretin hormone secreted by duodenal K-cells in response to fat and carbohydrate ingestion. Like GLP-1, it enhances glucose-dependent insulin secretion. Unlike GLP-1, it also promotes insulin secretion during hypoglycemia, protects β-cells, and at high doses may stimulate glucagon in a glucose-independent manner. The GIP receptor's role in energy homeostasis underlies the efficacy of dual GIP/GLP-1 agonists like tirzepatide.