Temporal-spatial expression of ANG-(1-7) and angiotensin-converting enzyme 2 in the kidney of normal and hypertensive pregnant rats

Am J Physiol Regul Integr Comp Physiol. 2007 Jul;293(1):R169-77. doi: 10.1152/ajpregu.00387.2006. Epub 2007 Apr 11.

Abstract

We recently demonstrated that renin-angiotensin system (RAS) overactivity during late gestation in rats is associated with increased kidney and urine levels of ANG-(1-7) and enhanced kidney immunostaining of ANG-(1-7) and angiotensin-converting enzyme 2 (ACE2). To understand the temporal-spatial changes in normal and hypertensive pregnancies, the renal distribution of ANG-(1-7) and ACE2 in association with kidney angiotensin peptides and ACE2 activity was examined in virgin, normal pregnant (NP; gestational days 5, 15, and 19) and reduced uterine perfusion pressure (RUPP at day 19) pregnant Sprague-Dawley rats. ANG-(1-7) and ACE2 immunocytochemical staining increased 1.8- and 1.9-fold and 1.7- and 1.8-fold, respectively, at days 15 and 19 of NP, compared with virgin rats. ANG-(1-7) and ANG II concentrations were increased in the kidney at 19 days of gestation. ACE2 activity measured using a fluorescent substrate was increased 1.9- and 1.9-fold in the cortex and 1.9- and 1.8-fold in the medulla at days 15 and 19 of NP. In the RUPP animals, ANG-(1-7) immunostaining and concentration were significantly decreased compared with 19-day NP rats. ACE2 activity was unchanged in the cortex and medulla of RUPP rats. In conclusion, during NP, the concurrent changes of ACE2 and ANG-(1-7) suggest that ACE2 plays an important role in regulating the renal levels of ANG-(1-7) at mid to late gestation. However, the decrease in renal ANG-(1-7) content in the absence of a concomitant decrease in ACE2 implicates the participation of other ANG-(1-7) forming or degrading enzymes during hypertensive pregnancy.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Angiotensin I / biosynthesis*
  • Angiotensin-Converting Enzyme 2
  • Angiotensinogen / metabolism
  • Animals
  • Blood Pressure / physiology
  • Body Weight / physiology
  • Estradiol / urine
  • Female
  • Fluorescent Antibody Technique
  • Hypertension, Pregnancy-Induced / enzymology
  • Hypertension, Pregnancy-Induced / metabolism*
  • Immunohistochemistry
  • Kidney / enzymology
  • Kidney / metabolism*
  • Peptide Fragments / biosynthesis*
  • Peptidyl-Dipeptidase A / biosynthesis*
  • Pre-Eclampsia / metabolism
  • Pre-Eclampsia / physiopathology
  • Pregnancy
  • Pregnancy, Animal / metabolism*
  • Proteinuria / metabolism
  • Rats
  • Rats, Sprague-Dawley
  • Regional Blood Flow / physiology
  • Renin / metabolism
  • Urodynamics / physiology
  • Uterus / blood supply

Substances

  • Peptide Fragments
  • Angiotensinogen
  • Estradiol
  • Angiotensin I
  • Peptidyl-Dipeptidase A
  • Ace2 protein, rat
  • Angiotensin-Converting Enzyme 2
  • Renin
  • angiotensin I (1-7)