EFFECT OF N-DICYCLOPROPYLMETHYL-AMINO-2-OXAZOLINE (S-3341) ON ANTIOXIDANT STATUS AND NITRIC-OXIDE IN HYPERTENSIVE PATIENTS

Defective endothelium-dependent vascular relaxation has been found in animal models of hypertension and in hypertensive patients. An inbalan ce due to reduced production of nitric oxide (NO) or increased product ion of free radicals, mainly the superoxide anion, may facilitate the development of an arterial functional spasm. Although it has been show n that many antihypertensive drugs can normalise both tire antioxidant activity and NO, the antioxidant effect of N-dicyclopropylmethyl-amin o-2-oxazoline (S-3341), an alpha-adrenoreceptor agonist, has not been investigated. In this study the investigated tire antioxidant and NO s tatus in hypertensive patients and whether there was any effect of S-3 341 or? these parameters. Eleven patients with mild hypertension (mean systolic blood pressure 159.5 +/- 2.5 mmHg) were administered S-3341 (1 mg/day) for 4 weeks. Plasma vitamin E, nitrite-nitrate and MDA leve ls, and catalase activity, were measured both before and after treatme nt with S-3341. There was significant reduction in both mean systolic and diastolic blood pressure during the treatment. We found an increas e irt catalase activity (p < 0.05), a decrease in malondialdehyde (MDA ) levels (p < 0.01) and an insignificant increase in vitamin E In els in hypertensive patients following tire S-3341 treatment. We propose t hat S-3341 may prevent oxidant stress in hypertensive patients by inhi biting free-radical formation.