The Study On The Correlation Of Vascular Endothelial Dysfunction And Oxidative Stress In Patients With Essential Hypertension

Objective Recently, there is growing body of evidence suggesting that oxidative stress, a state of excessive reactive oxygen species , impairs vascular endothelial function. Especially, increased superoxide anion production can lead to the decrease of nitric oxide of vascular endothelial cells , the increase of nitric oxide breakdown, or a loss of nitric oxide bioavailability. Superoxide anion interferes with nitric oxide (NO)-dependent vasodilation, participates in endothelium-dependent constriction, contributes to vascular smooth muscle cells growing and hypertrophy, and results in vascular remodeling .As a result, oxidative stress may involves in the generation and the development of hypertension and target organ damage. We examine the correlation of vascular endothelial function and oxidative stress by detecting the serum level of nitric oxide, malonyldialdehyde (MDA) content and the activities of superoxide dismutase(SOD) in patients with essential hypertension. Methods We selected 30 patients with essential hypertension( systolic ≥140 mmHg, diastolic≥90 mmHg), and 28 normatensive subjects(the control group), excluding secondary hypertension, diabetes mellitus, coronary atherosclerotic heart disease, heart failure, renal diseases, and connectivetissue disease. Body mass index were recorded. Plasma glucose, triglyceride, cholesterol, lowdensity lipoprotein and highdensity lipoprotein were measured .The level of NO, MDA content and the activities of SOD were measured respectively by nitrate reductase, thiobarbituric acid and xanthine oxidase methods. Results 2 groups were matched for age, sex, BMI and serum cholesterol levels. In 30 patients with essential hypertension, by comparison with the control group, the serum level of N0(106. 03±61. 82versusl40. 52±61. 13Wnol/L, P<0. 05), and the activities of S0D(107.03 ± 18.94versusll9.75 ± 20.09nU/ml, P <0.05) were significally decreased, and MDA content(7. 08 ± 2. 23versus5. 63 ± 1. 52, P <0. 01) were significally elevated. Conclusion The results suggest that there is the increase of reactive oxygen species and the decrease of antioxidative capacity in essential hypertension. Superoxide anion can reduce the level of NO, which supports the notion that oxidative stress was at least in part involved in the pathogenesis of essential hypertension. Vascular endothelial dysfunction was related to the enhanced activities of reactive oxygen species and oxidative stress.