The Effect of Various States of Hydration and the Plasma Concentration on the Turnover of Antidiuretic Hormone in Mammals *

Abstract

The turnover rates of endogenous and exogenous antidiuretic hormone (ADH) (Arginine-Vasopressin) were determined in dogs, rats, and patients with vasopressin-sensitive and vasopressin-resistant diabetes insipidus by utilizing a sensitive bioassay technique. In the rat and dog at higher plasma levels the turnover of the hormone was more rapid. In all 4 patients the hormonal turnover was significantly faster than observed in normal subjects during comparable states of hydration. It was concluded that both the plasma level of ADH and the state of hydration influenced the peripheral disposal of the hormone. The volume of distribution of ADH, determined by a constant infusion technique, and the rate of disappearance of the hormone after stopping the infusion, approximated the assumed plasma volume. This was substantiated by finding less than 1 [mu]U/ml in lymph at a time when the plasma level was above 200[mu]U/ml.