Reactive oxygen species and antioxidant status in essential arterial hypertension during therapy with dihydropyridine calcium channel antagonists.

PURPOSE: To evaluate reactive oxygen species and antioxidant status in essential arterial hypertension during therapy with dihydropiridine calcium channel antagonists. PATIENTS AND METHODS: Fifteen patients, affected by essential arterial hypertension, were examined. They received once a day oral dihydropyridine calcium antagonists for 10 weeks: five patients received felodipine (5 mg), five amlodipine (10 mg) and five lercanidipine (10 mg). The levels of end products of lipid peroxidation, free radicals and hydroperoxides and total antioxidant capacity were determined in the plasma of all subjects before and during treatment. Values are expressed as mean +/- S.E. Systolic blood pressure decreased from 171 +/- 4 to 135 +/- 6 mmHg (p < 0.01) and diastolic blood pressure decreased from 99 +/- 5 to 82 +/- 3 mmHg (p < 0.01). Hydroperoxides and free radicals decreased from 321.3 +/- 8.96 to 247.9 +/- 8.69 units (p < 0.01) and the end products of lipid peroxidation decreased from 11.0 +/- 1.93 to 6.74 +/- 1.41 nmol/ml (p < 0.01). Total antioxidant capacity increased from 0.74 +/- 0.03 to 1.05 +/- 0.05 mmol/l (p < 0.01).
RESULTS: Imbalance in the pro-oxidant-antioxidant equilibrium shifts in favour of antioxydant namely oxidative stress decreases. The calcium channel antagonists decrease peripheral arterial resistances and therefore decrease or abolish relative ischaemia, moreover decrease arterial pressure and therefore normalize parietal stress on endothelial cells. As a conseguence they act on two hypothesized mechanisms of oxidative stress in hypertension.
CONCLUSIONS: Dihydropyridine calcium antagonists used in this trial seem useful in hypertension because they decrease oxidative stress, and normalize of pressure values.