The investigation of the effect of resveratrol supplementation on vasoconstriction in long term fructose-treated rats


Institution Of The Thesis: Gazi University, Sağlık Bilimleri Enstitüsü, Turkey

Approval Date: 2009

Thesis Language: Turkish

Student: YASİN ATACAN AYTEKİN

Consultant: FATMA AKAR

Abstract:

The use of fructose is being increased in processed foods and beverages, because it extends their shelf life. High fructose intake causes insulin resistance, hypertriglyceridemia and hypertension. The harmful effects of increased fructose intake on health and their prevention should take greater consideration. Resveratrol has beneficial effects on endothelial and vascular function which is important in the prevention of cardiovascular disease. However, very little is known about the effect of resveratrol on fructose-induced vascular dysfunction. Therefore, in this study, we assessed whether chronic resveratrol administration changes vascular contractility in association with biochemical parameters, in fructose-treated rats. We investigated the effect of long-term resveratrol treatment (50 mg//L in drinking water for 12 weeks) on vascular contractility to KCl (40 mM), phenylephrine (10-9-3x10-4 M) and angiotensin II (10-10-10-5 M) in either endothelium-intact or denuded aortae from control and fructose-treated (10 and 20% fructose in drinking water for 10 weeks) rats. Blood pressure and serum lipids, insulin, glucose and fructosamine were also evaluated. Our results showed that fructose administration in drinking water for a period 10 weeks caused a modest increase in blood pressure, serum insulin without a change in body weight, serum lipid profile and glucose concentration. Fructose consumption caused an increase the contractions to KCl and phenylephrine in aortae from rat. Long-term resveratrol supplementation suppressed increased vascular contractility. Resveratrol treatment also depressed angiotensin II-induced contractions in both control and fructose groups. Additionally, insulin resistance and hypertension in fructose fed rats were also restrained in resveratrol supplemented rats. Resveratrol and fructose did not significantly change blood glucose level. The presented results showed that high fructose-induced cardiovascular abnormalities could be prevented by resveratrol pretreatment.