In 118 young men of 18-40 years old with high normal BP and the 1st grade arterial hypertension the concentrations of stable metabolites of NO (NO2–, NO3–) and NO-synthase activity in plasma and in erythrocytes were studied. Endothelium-dependant vasodilatation in brachial artery was observed in all patients. Presence of endothelial dysfunction is seen in 30.2 % patients with high normal BP and 29.4 % patients with 1st degree arterial hypertension. Endothelium dysfunction in patients with high normal BP is accompanied with decreased deposition of stable metabolites of NO in erythrocytes, decreased level of NO2– in plasma and erythrocytes and increased NO-synthase activity in erythrocytes. Endothelium dysfunction in patients with 1st degree arterial hypertension is accompanied with decrease in stable metabolites of NO in plasma as NO3– decreases and tendency to decrease NO-synthase activity in plasma.
