THE INVESTIGATION OF THE EFFECT OF RESVERATROL SUPPLEMENTATION ON VASORELAXATION IN LONG-TERM FRUCTOSE-TREATED RATS


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

Approval Date: 2009

Thesis Language: Turkish

Student: Ali AYDIN

Consultant: FATMA AKAR

Abstract:

High fructose intake is one of the main causes of metabolic syndrome in industrialized populations. Resveratrol, a polyphenolic compound mainly abundant in fruits, has beneficial cardiovascular effects. However, it is not known about the effect of resveratrol on fructoseinduced endothelial dysfunction. Therefore, In this study, we investigated whether long-term resveratrol supplementation changes endothelial reactivity, in association with biochemical parameters, in fructose-treated rats. We studied the effect of long-term resveratrol treatment (50 mg/L in drinking water for 12 weeks) on endothelial relaxation to acetylcholine (10- 9-10-4 M) and sodium nitroprusside (SNP, 10-10-10-5 M) in endotheliumintact 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 levels were also measured. Fructose consumption caused a modest increase in blood pressure, serum insulin without a change in body weight, serum lipid profile and glucose concentration. Fructose administration caused reduced relaxation to acetylcholine without changing the response to SNP. These changes were associated with increased basal nitric oxide production. The relaxations in response to acetylcholine disappeared after pretreatment with L-NOARG (10-4M). Chronic resveratrol treatment prevented endothelial dysfunction, normalized basal nitric oxide production. Resveratrol also restored insulin resistance and hypertension in fructose fed rats. Resveratrol and fructose did not significantly change blood glucose level. The presented data indicated that high fructose-induced disturbance in cardiovascular function could be prevented by resveratrol treatment. This implicates that consumption of fruits with fructose and resveratrol, like grape may not be deleterious as fructose containing beverages.