Dietary Na and ACE inhibition effects on renal tissue angiotensin I and II and ACE activity in rats

Am J Physiol. 1992 May;262(5 Pt 2):F902-9. doi: 10.1152/ajprenal.1992.262.5.F902.


This study was designed to improve and validate methods for the accurate and consistent quantitation of angiotensin (ANG) I and II levels in rat kidney and to determine the effects on renal ANG I and II of changes in dietary sodium intake and ANG-converting enzyme (ACE) inhibition. Kidneys from pentobarbital-anesthetized rats were rapidly removed and homogenized in methanol before extraction and purification of ANG peptides by solid-phase extraction and high-performance liquid chromatography (HPLC). Recoveries of 125I-ANG I and II were greater than 80%. Reversed-phase HPLC of the partially purified methanol extract showed that greater than 75% of the ANG I- and greater than 82% of the ANG II-like immunoreactivity coeluted with ANG I and II, respectively. Dietary sodium deprivation (0.003 meq/g) and excess (1.34 meq/g) for 7 days significantly (P less than 0.01) increased and decreased renal ANG I (296 +/- 30 and 82.6 +/- 15.8 vs. 161 +/- 18 fmol/g) and ANG II (216 +/- 16 and 45.6 +/- 11.8 vs. 98 +/- 16 fmol/g) contents, respectively. Plasma ANG I and II levels showed similar changes. ACE activity was significantly upregulated by sodium deprivation in both kidney (44% increase) and plasma (30% increase). In rats fed normal chow, infusion of enalaprilat for 1 h abolished plasma ACE activity but decreased renal ACE activity by only 58%. ACE inhibition increased renal and plasma ANG I levels 2.8- and 12-fold, respectively, and decreased renal and plasma ANG II levels 75-78%.(ABSTRACT TRUNCATED AT 250 WORDS)

Publication types

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

MeSH terms

  • Angiotensin I / metabolism*
  • Angiotensin II / metabolism*
  • Angiotensin-Converting Enzyme Inhibitors / pharmacology*
  • Animals
  • Chromatography, High Pressure Liquid
  • Diet
  • Kidney / metabolism*
  • Male
  • Peptidyl-Dipeptidase A / metabolism*
  • Rats
  • Rats, Inbred Strains
  • Renin-Angiotensin System / drug effects
  • Sodium / administration & dosage*
  • Sodium / pharmacology


  • Angiotensin-Converting Enzyme Inhibitors
  • Angiotensin II
  • Angiotensin I
  • Sodium
  • Peptidyl-Dipeptidase A