antidiuretic hormone (adh) is synthesized in the hypothalamus and is released at the
Antidiuretic hormone (ADH) (vasopressin). Peptide hormone synthesized in hypothalamus and released from posterior pituitary gland; increases water permeability of kidneys' collecting ducts and causes vasoconstriction.ntidiuretic hormone (ADH) (vasopressin). Peptide hormone synthesized in hypothalamus and released from posterior pituitary gland; increases water permeability of kidneys' collecting ducts and causes vasoconstriction.