Effect of doxazosin on oxidative stress related proteins in essential hypertensive patients

The role of oxidative stress in the pathophysiology of hypertension has stimulated the investigation of strategies to reduce oxidative stress via antioxidant defenses. Using a molecular biology approach, we report, in essential hypertensive patients, the effect of doxazosin treatment on the mononuclear cell gene and protein expression of two major elements in the oxidative stress and vascular remodeling-related pathways: p22(phox) and PAI-1. Ten essential hypertensive patients were treated with Doxazosin (4 mg/day) for two weeks (EH + D) and compared with ten untreated hypertensive patients (EH) and ten normotensive subjects (C). In EH p22(phox) and PAI-1 mRNA and protein level was increased compared with C. In EH + D, doxazosin reduced p22(phox) and PAI-1 gene and protein expression, which was similar to that of C. These results demonstrate for doxazosin an inhibitory effect on oxidative stress related proteins at gene and protein level, which confirms at molecular level a powerful antioxidant potential for this agent that could translate, in the long term, into a powerful antiatherosclerotic effect.

[Antioxidants, carnitine and erythropoietin]

Patients with renal disease possess an excess of cardiovascular (CV) risk factors, which predispose these patients to a high rate of morbidity and mortality due to CV disease. Oxidative stress and oxidative stress induced apoptosis play an important role not only in the pathophysiology and progression of renal disease, but also in the induction of myocardial damage and heart failure with important implications concerning CV morbidity and mortality in general, and particularly for patients with renal disease. This has stimulated the realization of studies aimed at evaluating therapies with antioxidants, given the evidence that patients with renal disease and heart failure have an imbalance towards pro-oxidant factors. The correction of anemia with erythropoetin (EPO) is another important aspect related to oxidative stress and apoptosis, which has also revealed positive effects for the improvement in heart failure. EPO cellular mechanisms are not completely known, and the identification of close biochemical and molecular relationships between EPO and heme oxygenase-1 (HO-1), which has potent antioxidant and anti-apoptotic properties, could provide the rationale for the beneficial effect of carnitine having been shown to possess antioxidant, anti-apoptotic and erythropoietic activities and to induce HO-1 expression, not only in dialysis patients who fail to respond adequately to EPO, but also in patients with heart failure. The identification of these relationships between EPO, HO-1 and carnitine and their biochemical mechanisms could contribute to the opening of new perspectives in the improvement of CV mortality in these patients, which remains the most important cause of death in patients with end-stage renal disease.