Rate of disappearance of arginine vasopressin from circulating blood in the dog

¹ Department of Physiology, Western Reserve University School of Medicine, Cleveland, Ohio

The half-life of arginine vasopressin was determined in dogs anesthetized with sodium pentobarbital. The rate of disappearance of the hormone from the circulating blood could be best described by a single exponential function during the time period studied. The average half-life of antidiuretic hormone (ADH) in eight dogs was 5.9 min with a standard error of 0.8. It appeared to be independent of the total amount of ADH administered and of whether the ADH was given as a 30-min infusion or as a single short injection. The volume of distribution of ADH, estimated in three dogs, was appreciably greater than blood volume.