Angiotensin-(1-7) stimulates water transport in rat inner medullary collecting duct: evidence for involvement of vasopressin V2 receptors

Pflugers Arch. 2003 Nov;447(2):223-30. doi: 10.1007/s00424-003-1173-1. Epub 2003 Oct 8.


The peptide angiotensin-(1-7) [Ang-(1-7)] is known to enhance water transport in rat inner medullary collecting duct (IMCD). The aim of this study was to determine the mechanism of the Ang-(1-7) effect on osmotic water permeability (Pf). Pf was measured in the normal rat IMCD perfused in vitro in presence of agonists [Ang-(1-7), arginine vasopressin (AVP) and Ang-(3-8)], and antagonists of the angiotensin and the vasopressin cascade. Ang-(1-7), but not Ang-(3-8), increased Pf significantly. The effect of Ang-(1-7) on Pf was abolished by its selective antagonist, A-779, added before or after Ang-(1-7). Prostaglandin E2 and the protein kinase A inhibitor H8 also blocked the Ang-(1-7) effect. Blockade of vasopressin V1 receptors by antagonists did not change the Ang-(1-7) effect, but pre-treatment with a V2 antagonist abolished the effect of Ang-(1-7) on Pf. Similarly, pre-treatment with A-779 inhibited AVP's effect on Pf. Forskolin-stimulated Pf was blocked both by A-779 and by the V2 antagonist. Finally, Ang-(1-7) increased cAMP levels in fresh IMCD cell suspensions whilst the forskolin-stimulated cAMP synthesis was decreased by A-779 and the V2 antagonist. These data provide evidence that Ang-(1-7) interacts via its receptor with the AVP V2 system through a mechanism involving adenylate-cyclase activation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Angiotensin I / pharmacology*
  • Angiotensin II / analogs & derivatives*
  • Angiotensin II / pharmacology
  • Animals
  • Antidiuretic Hormone Receptor Antagonists
  • Biological Transport / drug effects
  • Biological Transport / physiology
  • Colforsin / pharmacology
  • Cyclic AMP / metabolism
  • Kidney Tubules, Collecting / metabolism*
  • Osmosis
  • Peptide Fragments / pharmacology*
  • Permeability / drug effects
  • Protein Isoforms / antagonists & inhibitors
  • Protein Isoforms / physiology
  • Rats
  • Receptors, Vasopressin / physiology*
  • Signal Transduction / physiology
  • Water / metabolism*


  • 7-Ala-angiotensin (1-7)
  • Antidiuretic Hormone Receptor Antagonists
  • Peptide Fragments
  • Protein Isoforms
  • Receptors, Vasopressin
  • Water
  • Angiotensin II
  • Colforsin
  • Angiotensin I
  • Cyclic AMP
  • angiotensin I (1-7)