Caerulein is a small, cyclic peptide hormone derived from the skin of certain amphibians, particularly the European green tree frog (Hyla cinerea). It belongs to the class of compounds known as caeruleins, which are characterized by their blue coloration. Caerulein is comprised of nine amino acid residues and exhibits potent biological activity.
In a physiological context, caerulein acts as an agonist for cholecystokinin receptors, specifically the CCK1 and CCK2 receptor subtypes. Upon binding to these receptors, caerulein stimulates various physiological responses in the digestive system. It primarily influences the gallbladder, inducing contraction and promoting the release of bile into the small intestine to aid in the digestion and absorption of fats.
Caerulein has also been found to affect pancreatic function by stimulating the release of digestive enzymes and inhibiting insulin secretion. Moreover, it can influence the motility and secretion of the stomach and intestines, potentially affecting gastrointestinal transit time.
Due to its pharmacological properties, caerulein has been utilized in medical research to study various aspects of gastrointestinal physiology and pathology, such as gallstone formation, pancreatitis, and motility disorders. Additionally, its potential as a diagnostic tool for investigating certain digestive disorders has been explored.
Overall, caerulein is a biologically active peptide hormone derived from amphibian skin, which plays a vital role in the regulation of digestive functions, particularly within the gallbladder, pancreas, stomach, and intestines.
