title: Immunohistochemical localization of endothelial nitric oxide synthase in endometrial tissue of women with unexplained infertility.
abstract: BACKGROUND
  Nitric oxide (NO) is a molecule that incorporates in many physiological processes of female reproductive system. Recent studies suggested the possible role of endothelial isoform of nitric oxide synthase (eNOS) enzyme in female infertility.
  
  
  OBJECTIVE
  The aim of this study is to evaluate the expression of endothelial nitric oxide synthase in endometrial tissue of women with unexplained infertility.
  
  
  METHODS
  In this case-control study a total of 18 endometrial tissues obtained from 10 women with unexplained infertility and 8 normal and fertile women by endometrial biopsy, 6 to 10 days after LH surge. Specimens were fixed in 4% paraformaldhyde fixative and frozen sectioned for semi-quantitative immunohistochemical evaluation using monoclonal anti-human eNOS antibody. Hematoxilin and Eosin was used for Histological dating.
  
  
  RESULTS
  Localization of endothelial nitric oxide synthase was seen in glandular and luminal epithelium, vascular endothelium and stroma in both fertile women and women with unexplained infertility. Although there were differences in immunoreactivity of glandular epithelium (p=0.44), vascular endothelium (p=0.60) and stroma (p=0.63) but only over-expression of eNOS in luminal epithelium (p=0.045) of women with unexplained infertility compared to fertile women was statistically significant (p<0.05).
  
  
  CONCLUSIONS
  This study suggests that changes in luminal expression of eNOS may influence receptivity of endometrium.
authors.affiliation: Shahid Beheshti University of Medical Sciences, Tehran, Iran. ; Department of Biology and Anatomical Sciences, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Tohid
authors.initials: T
authors.lastname: Najafi
authors.affiliation: Shahid Beheshti University of Medical Sciences, Tehran, Iran. ; Department of Biology and Anatomical Sciences, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Marefat
authors.initials: M
authors.lastname: Ghaffari Novin
authors.affiliation: Infertility Treatment Center, Aban Hospital, Tehran, Iran.
authors.forename: Jalil
authors.initials: J
authors.lastname: Pakravesh
authors.affiliation: Department of Biology and Anatomical Sciences, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Khadijeh
authors.initials: K
authors.lastname: Foghi
authors.affiliation: Department of Biology and Anatomical Sciences, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Fadayi
authors.affiliation: Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Gelareh
authors.initials: G
authors.lastname: Rahimi
keywords: Human endometrium; Immunohistochemistry; Unexplained infertility; eNOS