title: Ethinylestradiol and estradiol have different effects on oxidative stress and nitric oxide synthesis in human endothelial cell cultures.
abstract: OBJECTIVE
  To compare the effects of ethinylestradiol (EE) and 17β-estradiol (E(2)) on nitric oxide (NO) production and protection against oxidative stress in human endothelial cell cultures.
  
  
  METHODS
  Experimental study.
  
  
  METHODS
  Research laboratory.
  
  
  METHODS
  Human ECV304 endothelial cell cultures.
  
  
  METHODS
  The NO synthesis was determined by flow cytometry, and oxidative stress was determined by a cell viability assay, after exposure to hydrogen peroxide (H(2)O(2)) and stimulation of endothelial cells with EE at concentrations similar to those of a contraceptive containing 30 μg EE.
  
  
  METHODS
  The effects of EE were compared with those of E(2) at concentrations similar to those occurring during the follicular phase.
  
  
  RESULTS
  Ethinylestradiol did not increase NO synthesis and did not protect cells against oxidative stress. The viability of the cells incubated with E(2) in combination with H(2)O(2) was greater than the viability obtained with H(2)O(2) only or with H(2)O(2) in combination with EE. The cells stimulated with E(2) presented a significant increase in NO production compared with control.
  
  
  CONCLUSIONS
  In contrast to the effects of E(2), EE did not protect human ECV304 endothelial cells against oxidative stress and did not increase their production of NO.
authors.affiliation: Department of Gynecology and Obstetrics, Ribeirão Preto School of Medicine, University of São Paulo, Ribeirão Preto, Brazil.
authors.forename: Mayra Beraldo
authors.initials: MB
authors.lastname: Andozia
authors.forename: Carolina Sales
authors.initials: CS
authors.lastname: Vieira
authors.forename: Silvio Antônio
authors.initials: SA
authors.lastname: Franceschini
authors.forename: Maria Regina
authors.initials: MR
authors.lastname: Torqueti Tolloi
authors.forename: Marcos Felipe
authors.initials: MF
authors.lastname: Silva de Sá
authors.forename: Rui Alberto
authors.initials: RA
authors.lastname: Ferriani
mesh_terms: D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D004958:Estradiol / Q000494:pharmacology*; D004967:Estrogens / Q000494:pharmacology; D004997:Ethinyl Estradiol / Q000494:pharmacology*; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D009569:Nitric Oxide / Q000378:metabolism*; D018384:Oxidative Stress / Q000187:drug effects*
chemical_list: D004967:Estrogens; D009569:Nitric Oxide; D004997:Ethinyl Estradiol; D004958:Estradiol; D006861:Hydrogen Peroxide