Effect of nebivolol on blood oxygen transport indices and endothelial dysfunction in patients with arterial hypertension.

Endothelial dysfunction, which is characterized by impairment of nitric oxide (NO) bioavailability, plays an important role in the development of arterial hypertension. The L-arginine-NO pathway is closely related to oxygen transport to tissue. Endothelial dysfunction in patients with arterial hypertension can affect haemoglobin-oxygen affinity and tissue oxygen supply. Alterations in blood oxygen transport indices may play role in the pathogenesis of arterial hypertension. The aim of the present study was to investigate the effect of the beta-selective adrenoblocker nebilet (nebivolol) on blood oxygen transport indices and on endothelial dysfunction in patients with arterial hypertension. The study population included 52 patients with grade II and grade III arterial hypertension. The results of our studies indicate that endothelial dysfunction in hypertensive patients significantly changes blood oxygen indices. The endothelium can be involved in formation of these impairments because only NO synthesized in sufficient amounts can maintain normal blood flow and oxygen transport to tissues. Endothelial dysfunction impairs formation of different haemoglobin NO-derivatives, that influence not only on the release of NO at different sites of the vascular bed, but also on haemoglobin-oxygen affinity, and accordingly, on optimal blood oxygenation in capillaries of pulmonary circulation and its deoxygenation in capillaries of systemic circulation. Treatment of hypertensive patients with nebivolol corrects the blood oxygen transport indices, stimulates NO production and improves endothelium-dependent dilatation. Normalization of blood oxygen transport indices may regulate the activity of the L-arginine-NO pathway. Thus, nebivolol may improve efficiency of the treatment of hypertension.