antidiuretic hormone

n. (ADH) Also known as vasopressin, antidiuretic hormone helps regulate the retention of water in the body and the blood pressure. It is synthesized in the hypothalamus and released by nerve cells in the pituitary gland. It has the effect of causing the body to produce less urine and so retain more water and of constricting capillaries, both of which raise blood pressure. ADH is also part of the hypothalamic-pituitary-adrenocortical system, which controls overall metabolism and arousal.