Role of renal aquaporins in escape from vasopressin-induced antidiuresis in rat

J Clin Invest. 1997 Apr 15;99(8):1852-63. doi: 10.1172/JCI119352.

Abstract

The purpose of this study was to investigate whether escape from vasopressin-induced antidiuresis is associated with altered regulation of any of the known aquaporin water channels. After 4-d pretreatment with 1-deamino-[8-D-arginine]-vasopressin (dDAVP) by osmotic mini-pump, rats were divided into two groups: control (continued dDAVP) and water-loaded (continued dDAVP plus a daily oral water load). A significant increase in urine volume in the water-loaded rats was observed by the second day of water loading, indicating onset of vasopressin escape. The onset of escape coincided temporally with a marked decrease in renal aquaporin-2 protein (measured by semiquantitative immunoblotting), which began at day 2 and fell to 17% of control levels by day 3. In contrast, there was no decrease in the renal expression of aquaporins 1, 3, or 4. The marked suppression of whole kidney aquaporin-2 protein was accompanied by a concomitant suppression of whole kidney aquaporin-2 mRNA levels. Immunocytochemical localization and differential centrifugation studies demonstrated that trafficking of aquaporin-2 to the plasma membrane remained intact during vasopressin escape. The results suggest that escape from vasopressin-induced antidiuresis is attributable, at least in part, to a vasopressin-independent decrease in aquaporin-2 water channel expression in the renal collecting duct.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Aquaporin 2
  • Aquaporin 3
  • Aquaporin 6
  • Aquaporins*
  • Base Sequence
  • Cell Membrane Permeability / drug effects
  • Cell Membrane Permeability / physiology
  • DNA Primers / genetics
  • Deamino Arginine Vasopressin / pharmacology*
  • Diuresis / drug effects*
  • Diuresis / physiology*
  • Ion Channels / genetics
  • Ion Channels / physiology*
  • Kidney / drug effects*
  • Kidney / physiology*
  • Kidney Tubules, Collecting / drug effects
  • Kidney Tubules, Collecting / physiology
  • Kinetics
  • Male
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Rats
  • Rats, Sprague-Dawley
  • Renal Agents / pharmacology
  • Water / metabolism

Substances

  • Aqp2 protein, rat
  • Aqp3 protein, rat
  • Aquaporin 2
  • Aquaporin 6
  • Aquaporins
  • DNA Primers
  • Ion Channels
  • RNA, Messenger
  • Renal Agents
  • Water
  • Aquaporin 3
  • Deamino Arginine Vasopressin