Vasopressin, also known as arginine vasopressin (AVP), antidiuretic hormone (ADH), or argipressin, is a neurohypophysial hormone found in most mammals. Its two primary functions are to retain water in the body and to constrict blood vessels.asopressin is a peptide hormone that increases water permeability of the kidney's collecting duct and distal convoluted tubule by inducing translocation of aquaporin-CD water channels in the plasma membrane of collecting duct cells.