Distribution of angiotensin-(1-7) and ACE2 in human placentas of normal and pathological pregnancies

Placenta. 2006 Feb-Mar;27(2-3):200-7. doi: 10.1016/j.placenta.2005.02.015. Epub 2005 Apr 25.


This work was designed to study the expression of the vasodilator peptide angiotensin-(1-7) [Ang-(1-7)] and its generating enzyme (ACE2) in the uteroplacental interface. Placentas were obtained from 11 early pregnancy failures (5 miscarriages and 6 ectopic pregnancies), 15 normotensive, and 10 preeclamptic gestations. In placental villi, the main sites of immunocytochemical expression of Ang-(1-7) and ACE2 were the syncytiotrophoblast, cytotrophoblast, endothelium and vascular smooth muscle of primary and secondary villi. Syncitial Ang-(1-7) expression in samples obtained from miscarriages and ectopic pregnancies was increased compared to normal term pregnancy [2.0 (2.0-2.25 for the 25 and 75% interquartile range) vs 1.3 (1.0-1.9), p<0.01]. In the maternal stroma, Ang-(1-7) and ACE2 were expressed in the invading and intravascular trophoblast and in decidual cells in all 3 groups. Ang-(1-7) and ACE2 staining was also found in arterial and venous endothelium and smooth muscle of the umbilical cord. The expression of Ang-(1-7) and ACE2 was similar in samples obtained from normal term or preeclamptic pregnancies, except for increased expression of ACE2 in umbilical arterial endothelium in preeclampsia [0.5 (0.5-0.8) vs 0.0 (0.0-0.0), p<0.01]. The uteroplacental location of Ang-(1-7) and ACE2 in pregnancy suggests an autocrine function of Ang-(1-7) in the vasoactive regulation that characterizes placentation and established pregnancy.

Publication types

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

MeSH terms

  • Angiotensin I / analysis*
  • Angiotensin I / metabolism
  • Angiotensin-Converting Enzyme 2
  • Carboxypeptidases / analysis*
  • Carboxypeptidases / metabolism
  • Female
  • Humans
  • Immunohistochemistry
  • Peptide Fragments / analysis*
  • Peptide Fragments / metabolism
  • Peptidyl-Dipeptidase A
  • Placenta / chemistry*
  • Placenta / enzymology
  • Placenta / metabolism
  • Pre-Eclampsia / metabolism
  • Pregnancy / metabolism*
  • Pregnancy Complications / enzymology
  • Pregnancy Complications / metabolism*


  • Peptide Fragments
  • Angiotensin I
  • Carboxypeptidases
  • Peptidyl-Dipeptidase A
  • ACE2 protein, human
  • Angiotensin-Converting Enzyme 2
  • angiotensin I (1-7)