Copeptin, a stable peptide of the arginine vasopressin precursor, is elevated in hemorrhagic and septic shock.Arginine vasopressin (AVP) levels are increased in hemorrhagic and septic shock. Measurement of AVP levels has limitations due to its short half-life and cumbersome detection method. Copeptin is a more stable peptide derived from the same precursor molecule.C-Terminal Provasopressin (Copeptin) as a Novel and Prognostic Marker in Acute Myocardial Infarction.

arginine vasopressin-neurophysin II is a precursor protein consisting of arginine vasopressin and two associated proteins, neurophysin II and a glycopeptide, copeptin. Arginine vasopressin is a posterior pituitary hormone which is synthesized in the supraoptic nucleus and paraventricular nucleus of the hypothalamus.