title: Effects of estrogen replacement therapy on vascular endothelial growth factor expression in choroidal and retinal vasculature.
abstract: OBJECTIVE
  To investigate the effects of estrogen replacement therapy (ERT) on vascular endothelial growth factor (VEGF) expression in choroidal and retinal vasculature in experimental rat model.
  
  
  METHODS
  Forty female Wistar rats were randomized in 4 groups in the study. Subcutaneous ERT (17beta-estradiol, 10 microg/kg/day) was administered for three months to first group without ovariectomy and to second group with ovariectomy. Rats in third group had only ovariectomy and fourth group had sham operation. At the end of the third month, all rats were sacrificed in estrous cycles determined by vaginal smear test and their right eyes were enucleated. Enucleated eyes were analyzed by immunohistochemical method for expression of VEGF.
  
  
  RESULTS
  Only ovariectomy (group 3) in rats did not change VEGF expression than the sham operated (group 4) rats. However, there was more VEGF expression in groups receiving ERT than the group 3 and 4, but increased VEGF expression was statistically significant in group 1 in comparison to group 3, and 4 in both, choroidal and retinal vasculature.
  
  
  CONCLUSIONS
  It was shown that ERT increases VEGF expression in choroidal and retinal vasculature, in particular in non-ovariectomized rats. Our findings suggest that ERT may be a risk factor for choroidal and retinal angiogenesis. Further studies are needed to evaluate the risks or benefits of exogenous estrogen supplementation for the choroidal and retinal angiogenesis in women (Fig. 2, Ref. 25).
authors.affiliation: Department of Ophthalmology, Adnan Menderes University School ofMedicine, Aydin, Turkey.
authors.forename: S O
authors.initials: SO
authors.lastname: Dundar
authors.forename: F
authors.initials: F
authors.lastname: Ozcura
authors.forename: E D
authors.initials: ED
authors.lastname: Cetin
authors.forename: N
authors.initials: N
authors.lastname: Beder
authors.forename: M
authors.initials: M
authors.lastname: Dundar
mesh_terms: D000818:Animals; D001808:Blood Vessels / Q000378:metabolism; D002829:Choroid / Q000098:blood supply* / Q000378:metabolism; D004958:Estradiol / Q000494:pharmacology*; D015914:Estrogen Replacement Therapy; D005260:Female; D007150:Immunohistochemistry; D010052:Ovariectomy; D051381:Rats; D017208:Rats, Wistar; D012171:Retinal Vessels / Q000378:metabolism*; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism*
chemical_list: D042461:Vascular Endothelial Growth Factor A; D004958:Estradiol