Vasopressin, also known as arginine vasopressin (AVP) or antidiuretic hormone (ADH), is a posterior pituitary hormone that is synthesised in the hypothalamus. Vasopressin is synthesised as a precursor protein that consists of arginine vasopressin and two associated proteins, neurophysin 2 and the glycopeptide copeptin. Vasopressin, together with its carrier protein neurophysin II, is packaged into neurosecretory vesicles and transported axonally to the nerve endings in the neurohypophysis, w