Ceruletide, also known as cerulein or caerulein, is a ten amino acid oligopeptide that stimulates smooth muscle and increases digestive secretions. Ceruletide is similar in action and composition to cholecystokinin. 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 in experimental animal models. The tree frog Litoria caerulae, formerly named Hyla caerulae.Ceruletide was discovered and its structure elucidated from dried skins of the Australian green tree frog. Its amino acid sequence is Pglu-Gln-Asp-Tyr[SO3H]-Thr-Gly-Trp-Met-Asp-Phe-NH2.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.