Angiotensin-(1-7), its receptor Mas, and the angiotensin-converting enzyme type 2 are expressed in the human ovary

Objective: To investigate whether angiotensin (Ang)-(1-7), its receptor Mas, and angiotensin-converting enzyme type 2 (ACE2) are present in human ovary. Design: Cross-sectional study. Setting: Academic hospital. Patient(s): Twelve reproductive-age women and five postmenopausal women undergoing oophorectomy for nonovarian diseases and seven women having controlled ovarian hyperstimulation for IVF. Intervention(s): Ovarian tissue was obtained from the reproductive-age women and postmenopausal women undergoing oophorectomy for nonovarian diseases. Follicular fluid (FF) samples were obtained from the women having controlled ovarian hyperstimulation for IVF. Main Outcome Measure(s): Localization of Ang-(1-7) and Mas by immunohistochemistry; measurement of Ang( 1-7) in ovarian FF by RIA; detection of messenger RNAs encoding Mas and ACE2 with use of real-time polymerase chain reaction; assessment of 125 I-labeled Ang-(1-7) binding to ovarian sections with use of autoradiographic binding assay. Result(s): Angiotensin-(1-7) and the receptor Mas were localized to primordial, primary, secondary, and antral follicles, stroma, and corpora lutea of reproductive-age ovaries. Postmenopausal women expressed both the peptide and its receptor in the ovarian stroma. Angiotensin-(1-7) was detectable in FF (mean +/- SE: 191 +/- 54 pg/mL). Both Mas and ACE2 messenger RNAs were expressed in ovarian tissue, as revealed by real-time polymerase chain reaction, and ovarian binding sites for 125 I-labeled Ang-(1-7) were identified by autoradiography. Conclusion(s): Angiotensin-(1-7), its receptor Mas, and ACE2 are expressed in the human ovary. The peptide is present in several ovarian compartments and can be quantified in FF. (Fertil Steril(R) 2011;95:176-81. (C) 2011 by American Society for Reproductive Medicine.)