RT Journal Article SR Electronic T1 THE PHYSIOLOGY OF MORPHINE ANTIDIURESIS JF Journal of Pharmacology and Experimental Therapeutics JO J Pharmacol Exp Ther FD American Society for Pharmacology and Experimental Therapeutics SP 431 OP 438 VO 113 IS 4 A1 JOHN D. CRAWFORD A1 BARBARA PINKHAM YR 1955 UL http://jpet.aspetjournals.org/content/113/4/431.abstract AB Studies of the influence of morphine phosphate on renal water and solute excretion have been carried out in rats and the changes due to morphine have been contrasted with those effected by Pitressin under similar experimental circumstances. The antidiuretic action of morphine has been shown to have two components. The first of these consists of a reduction in the rate of urine formation without change in its composition as regards the ratio of water to total solutes. This type of antidiuresis is similar to that which results from simple mechanical compression of the renal artery and is thus interpreted as the response to morphine induced changes in renal hemodynamics. The second component of the antidiuretic action of morphine is demonstrable only in the presence of preformed antidiuretic hormone. This consists of augmentation of the hormone's influence as measured by its effect on urine water concentration. Morphine does not appear to stimulate antidiuretic hormone release. Two possible explanations of the potentiation by morphine of neurohypophyseal antidiuretic hormone action are discussed. © 1955, by The Williams & Wilkins Company