Ethinylestradiol and estradiol have different effects on oxidative stress and nitric oxide synthesis in human endothelial cell cultures.
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.
Andozia
Mayra Beraldo
MB
Department of Gynecology and Obstetrics, Ribeirão Preto School of Medicine, University of São Paulo, Ribeirão Preto, Brazil.
Vieira
Carolina Sales
CS
Franceschini
Silvio Antônio
SA
Torqueti Tolloi
Maria Regina
MR
Silva de Sá
Marcos Felipe
MF
Ferriani
Rui Alberto
RA
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*
D004967:Estrogens; D009569:Nitric Oxide; D004997:Ethinyl Estradiol; D004958:Estradiol; D006861:Hydrogen Peroxide