Antioxidant Effects of Vitamins C and E Are Associated With Altered Activation of Vascular NADPH Oxidase and Superoxide Dismutase in Stroke-Prone SHR

• Published in: Hypertension (Dallas, Tex. 1979) Tex. 1979), 2001-09, Vol.38 (3, Part 2 Suppl), p.606-611
• Main Authors: Chen, Xin, Touyz, Rhian M, Park, Jeong Bae, Schiffrin, Ernesto L
• Format: Article
• Language: English
• Subjects: Acetylcholine - pharmacology; Animals; Antioxidants - pharmacology; Ascorbic Acid - pharmacology; Biological and medical sciences; Blood Pressure - drug effects; Blood Vessels - drug effects; Blood Vessels - metabolism; Blood Vessels - physiopathology; Dose-Response Relationship, Drug; Enzyme Activation - drug effects; General and cellular metabolism. Vitamins; Hypertension - enzymology; Hypertension - physiopathology; In Vitro Techniques; Medical sciences; Mesenteric Arteries - drug effects; Mesenteric Arteries - physiopathology; NADPH Oxidases - drug effects; NADPH Oxidases - metabolism; Nitroprusside - pharmacology; Norepinephrine - pharmacology; Pharmacology. Drug treatments; Rats; Rats, Inbred SHR; Superoxide Dismutase - drug effects; Superoxide Dismutase - metabolism; Superoxides - metabolism; Vasoconstriction - drug effects; Vasodilator Agents - pharmacology; Vitamin E - pharmacology
• ISSN: 0194-911X; 1524-4563
• DOI: 10.1161/hy09t1.094005

Ascorbic acid (vitamin C) and α-tocopherol (vitamin E) have antioxidant properties that could improve redox-sensitive vascular changes associated with hypertension. We determined whether vitamins C and E influence vascular function and structure in hypertension by modulating activity of NADPH oxidase and superoxide dismutase (SOD). Adult stroke-prone spontaneously hypertensive rats (SHRSP) were divided into 3 groupscontrol (C; n=6), vitamin C-treated (vit C, 1000 mg/day; n=7), and vitamin E-treated (vit E, 1000 IU/day; n=8). All rats were fed 4% NaCl. Blood pressure was measured weekly. After 6 weeks of treatment, the rats were killed, and mesenteric arteries were mounted as pressurized preparations. Vascular O2 generation and NADPH oxidase activity were measured by chemiluminescence. Vascular SOD activity and plasma total antioxidant status (TAS) were determined spectrophotometrically. Blood pressure increased from 212±7 to 265±6 mm Hg in controls. Treatment prevented progression of hypertension (vit C, 222±6 to 234±14 mm Hg; vit E, 220±9 to 227±10 mm Hg). Acetylcholine-induced vasodilation was improved (P