Endocrine Abstracts

Introduction: Limited data exist on testosterone and oxidative stress induction. The present study was undertaken to evaluate, in vitro, the role of physiological concentrations of androgens (testosterone-DHT) in modulating the pro-oxidant and antioxidant activity of intact endothelial cells.

Materials and methods: EA.hy926 macroendothelial cells were cultured in DMEM phenol red free without FBS for 24 hours. Growth medium was replaced and then testosterone (0.5 nM), and DHT (0.5 nM) alone or in combination with the androgen receptor antagonist flutamide (50nM), were added to the culture media and cells incubated for 2 more hours. Intracellular reactive oxygen species (ROS) content, endothelial nitric oxide synthase (eNOS) activity, nitric oxide (NO) levels, superoxide dismutase (SOD) activity, catalase activity (CAT), and glutathione (GSH) levels were measured.

Results: Testosterone and DHT significantly increased eNOS activity (P < 0.001 vs CTL) and NO production (P < 0.001, P < 0.01 vs CTL accordingly), while they augmented the intracellular ROS content (P < 0.001 vs CTL) in EA.hy926 endothelial cells. Moreover, they increased the antioxidative system of SOD (P < 0.001, P < 0.01 vs CTL accordingly) and significantly decreased catalase activity (P < 0.001 vs CTL). All the above effects of androgens were abolished by flutamide suggesting that they act through the androgen receptor. Finally, testosterone and DHT had no significant effect on cellular GSH levels and the GSH/GSH + GSSH ratio in EA.hy926 cells.

Conclusion: Our findings indicate a pro-oxidative role of testosterone and DHT in EA.hy926 endothelial cells, suggesting that the androgens upregulate the endothelial oxidoreductase homeostasis to a higher functional level.