Ceruletide (

INN Inns are generally establishments or buildings where travelers can seek lodging, and usually, food and drink. Inns are typically located in the country or along a highway; before the advent of motorized transportation they also provided accommo ...

), also known as cerulein or caerulein, is a ten amino acid

oligopeptide An oligopeptide, often just called peptide ('' oligo-'', "a few"), consists of two to twenty amino acids and can include dipeptides, tripeptides, tetrapeptides, and pentapeptides. Some of the major classes of naturally occurring oligopeptides in ...

that stimulates

smooth muscle Smooth muscle is an involuntary non- striated muscle, so-called because it has no sarcomeres and therefore no striations (''bands'' or ''stripes''). It is divided into two subgroups, single-unit and multiunit smooth muscle. Within single-unit ...

and increases digestive secretions. Ceruletide is similar in action and composition to

cholecystokinin Cholecystokinin (CCK or CCK-PZ; from Greek ''chole'', "bile"; ''cysto'', "sac"; ''kinin'', "move"; hence, ''move the bile-sac (gallbladder)'') is a peptide hormone of the gastrointestinal system responsible for stimulating the digestion of fat an ...

. It stimulates gastric, biliary, and pancreatic secretion; and certain smooth muscle. It is used in paralytic ileus and as diagnostic aid in pancreatic malfunction. It is used to induce

pancreatitis Pancreatitis is a condition characterized by inflammation of the pancreas. The pancreas is a large organ behind the stomach that produces digestive enzymes and a number of hormones. There are two main types: acute pancreatitis, and chronic p ...

in experimental animal models. Ceruletide was discovered and its structure elucidated in 1967 by Australian and Italian scientists from dried skins of the Australian green tree frog (''Ranoidea caerulea'', formerly ''Hyla caerulea''). Its amino acid sequence is Pglu-Gln-Asp-Tyr O₃HThr-Gly-Trp-Met-Asp-Phe-NH₂.

Induction of pancreatitis

Ceruletide upregulates pancreatic acinar cell intercellular adhesion molecule-1 (ICAM-1) proteins through intracellular upregulation of

NF-κB Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) is a protein complex that controls transcription of DNA, cytokine production and cell survival. NF-κB is found in almost all animal cell types and is involved in cellular ...

. Surface ICAM-1 in turn promotes neutrophil adhesion onto acinar cells enhancing pancreatic

inflammation Inflammation (from la, wikt:en:inflammatio#Latin, inflammatio) is part of the complex biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or Irritation, irritants, and is a protective response involving im ...

. In addition to promoting the inflammatory cell reaction to acinar cells, ceruletide induces pancreatitis through dysregulation of digestive enzyme production and cytoplasmic vacuolization, leading to acinar cell death and pancreatic edema. Ceruletide also activates

NADPH oxidase NADPH oxidase (nicotinamide adenine dinucleotide phosphate oxidase) is a membrane-bound enzyme complex that faces the extracellular space. It can be found in the plasma membrane as well as in the membranes of phagosomes used by neutrophil white ...

, a source of reactive oxygen species contributing to inflammation, as well as the

Janus kinase Janus kinase (JAK) is a family of intracellular, non-receptor tyrosine kinases that transduce cytokine-mediated signals via the JAK-STAT pathway. They were initially named "just another kinase" 1 and 2 (since they were just two of many discoverie ...

/signal transducer, another inflammation inducer.

References

{{Diagnostic agents Peptides

Induction of pancreatitis

See also

References