Selenium-dependent GSH-Px in erythrocytes of patients with hypertension treated with ACE inhibitors.

This study is aimed at examining whether essential arterial hypertension (HTN) or ACE inhibitors have any effect on erythrocyte selenium (Se)-dependent and Se-non-dependent glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) activity. Eleven patients with HTN (2 men and 9 women) and 9 healthy volunteers were included in this study after clinical examination and laboratory investigation. The activities of all three enzymes were determined and then the patients were assigned to receive ACE inhibitor therapy consisting of captopril, 25 to 50 mg daily, or enalapril, 10 to 40 mg daily. After 1 year, the determination of antioxidant enzymes was repeated. Our results showed that the initial values of Se-dependent GSH-Px in patients treated with ACE inhibitors were significantly lower (19.60 +/- 3.50 microM NADPH/min(-1)/mgHb(-1)) compared with the controls (28.64 +/- 4.93 microM NADPH/min(-1)/mgHb(-1); p < 0.001), whereas the activity of Se-non-dependent GSH-Px was significantly enhanced (13.55 +/- 1.46 microM NADPH/min(-1)/mgHb(-1); p < 0.001) compared with the control group (9.44 +/- 0.81 microM NADPH/min(-1)/mgHb(-1); p < 0.001). ACE inhibitors did not significantly change the activity of Se-dependent GSH-Px or Se-non-dependent GSH-Px. No significant alteration was observed in SOD activity.