Xenopsin

Xenopsin is a neurotensin-like octapeptide that has been found in X. laevis skin.{46783} It inhibits neurotensin (Item No. 24717) binding to rat brain synaptic membranes (Ki = 1.5 nM) and induces contraction of isolated guinea pig ileum in the presence of neostigmine (Item No. 23501; EC50 = 9 nM).{38912} Xenopsin (0.1 ?M) increases the firing rate of dopaminergic neurons in rat substantia nigra slices by 58.5%.{46784} Intravenous infusion of xenopsin (2 ?g/kg per hour) increases adrenal, pancreatic, and ileal blood flow and plasma levels of pancreatic polypeptide, glucagon, substance P, and cortisol, as well as reduces tetragastrin-induced gastric acid secretion in dogs.{46783}