ABSTRACT: Before menopause, women have a lower risk of cardiovascular diseases than men. Studies attribute this gender difference to
estrogenic protection in the female cardiovascular system. We have demonstrated that 17β-estradiol (E2) protects female bovine aortic endothelial cells against oxidative injury, probably through the induction of antioxidant
enzyme activities. In this study, we examined whether E2 confers a differential protection on male and female cells. Bovine aortic endothelial cells from both genders were preconditioned
for 24 h with E2 (1 nM to 10 µM), and their resistance to paraquat (1 mM, 3 h), a superoxide generator, was measured using an MTT assay. In contrast to the protection observed in female bovine aortic
endothelial cells, there was no protective effect by E2 on male bovine aortic endothelial cells at physiologic concentrations. However, E2 at 1–10 µM attenuated paraquat’s toxicity in both male and female cells, probably through its direct antioxidant activity. E2 at 1 nM increased in female, but not in male, cells the activities of super-oxide dismutase, catalase, glutathione peroxidase, and
glutathione reductase, which was associated with decreased levels of reactive oxygen species during subsequent paraquat exposure.
This suggests that antioxidant enzyme induction plays some role in E2-augmented oxidative resistance in female endothelial cells.
Endocrine 04/2012; 15(3):255-262. · 1.42 Impact Factor