The Effects of Resveratrol in Rats with Simultaneous Type 2 Diabetes and Renal Hypertension: a Study of Antihypertensive Mechanisms

BACKGROUND: Resveratrol has beneficial effects on cardiovascular system. This study aimed at examining antidiabetic and antihypertensive effects of resveratrol in rats with simultaneous type 2 diabetes and renal hypertension. METHODS: Eight groups (8-10 each) of male Spargue-Dawley rats, including a control, a diabetic (induced by streptozotocin and nicotinamide), a renal hypertensive (induced by placing plexiglas clips on the left renal arteries), a sham, a simultaneously hypertensive-diabetic receiving vehicle, and 3 simultaneous hypertensive-diabetic receiving resveratrol at 5, 10 or 20 mg/kg/day were used. Four weeks after the induction of diabetes, renal hypertension was induced and animals were given vehicle or resveratrol for the next four weeks. Afterwards, blood pressure and glucose, serum markers of oxidative stress were measured and animal’s aortic rings were used for isolated studies. RESULTS: Serum malondialdehyde, systolic blood pressure, heart rate, fasting blood glucose, maximal response and effective concentration 50 of phenylephrine, and inhibitory concentration 50 of acetylcholine of hypertensive-diabetic group receiving vehicle were significantly higher than those of the control group, and treatment with resveratrol caused significant reduction of these variables. Moreover, serum superoxide dismutase, glutathione reductase, and maximal response to acetylcholine of hypertensive-diabetic group receiving vehicle were significantly lower than those of the control group, and treatment with resveratrol caused significant increase of these variables. CONCLUSION: The findings indicate that resveratrol has antidiabetic and antihypertensive effects, which may be partly due to antioxidant mechanism. They also show that antihypertensive effect of resveratrol may be additionally mediated by improving the release of nitric oxide and sympathoplegic activities.