Antioxidant vitamins inhibit progression of hypertension and improve endothelial dysfunction and antioxidant status in SHRSP

• Published in: American journal of hypertension 2000-04, Vol.13 (4), p.20A-20A
• Main Authors: Touyz, R.M, Park, J.-B, Chen, X, Schiffrin, E.L
• Format: Article
• Language: English
• Subjects: endothelium; Oxidative stress; vascular remodeling
• ISSN: 0895-7061; 1879-1905; 1941-7225
• DOI: 10.1016/S0895-7061(00)00350-2

We investigated effects of vitamins C and E on blood pressure elevation, vascular remodeling and endothelial function in salt-loaded stroke-prone SHR (SHRSP). The role of oxidative stress was also assessed in these processes. 16 week-old SHRSP (n = 16) on a high salt diet (4% NaCl) were randomly divided into 3 groups: control (C), Vit C (1000 mg/d) and Vit E (1000 IU/d). Systolic blood pressure (SBP) and plasma antioxidant status (spectrophotometric assay system) were assessed weekly. 6 weeks after treatment rats were killed. Vascular structure (media:lumen ratio) and endothelial function (ACH-induced vasodilation) were assessed in mesenteric arteries. Vascular •O2− production was measured in aortic vessels using lucigenin (5 μM). SBP increased progressively from 204 ± 9.4 to 246 ± 5.6 mmHg in C group. Progression of hypertension was prevented in Vit C (210 ± 5 mmHg) and Vit E (209 ± 11 mmHg) groups. Ach-induced dilation was significantly improved in the treated groups. Media:lumen ratio was reduced (p < 0.001) in Vit E group (6.8 ± 0.8%) vs C group (12.3 ± 0.1%0. Total antioxidant status was significantly improved (p < 0.05) in the Vit C (1.3 ± 0.2 mM) and Vit E (1.68 ± 0.4 mM) groups compared with C (0.87 ± 0.1 mM). •O2− production was significantly lower in both Vit-treated groups compared with the untreated group. Vits C and E improved endothelial dysfunction in small arteries and prevented the progression of hypertension in salt-loaded SHRSP. Vit E also corrected vascular remodeling. These effects were associated with improved antioxidant status and reduced vascular oxidative stress. Thus beneficial effects of antioxidant vitamins in vascular damage associated with hypertension are related, in part, to alterations in vessel redox state.