AVP and Cirrhosis: To keep arterial blood pressure within normal limits for cirrhosis patients, clear activation forms in endogenous vasoconstrictor systems like the renin – angiotensin - aldosterone system, sympathetic nervous system and vasopressin (AVP).9 Copeptin, a 39 - amino acid glycopeptide, biochemically is released from the neurohypophysis within pioneer preprovasopressin together with AVP.