P107	The effect of long term resveratrol treatment on endothelial reactivity of aortae from female and male rats.
S.Söylemez, F.Akar
Gazi University, Faculty of Pharmacy, Department of Pharmacology, Ankara, TR.

Epidemiological studies indicate an association between moderate consumption of red wine and reduced risk of coronary heart disease. A naturally occuring phytoalexin resveratrol presented in red wine is proposed to possess cardioprotective effects. It has been shown that resveratrol has both endothelium dependent and endothelium independent vasodilatory effects in rat aorta, pig coronary artery, rat mesenteric artery,human saphenous ven and internal mamary artery. The aim of the present study is to evaluate the effect of long term resveratrol treatment on endothelial responsiveness to phenylephrine and acetylcholine on aorta from male and female Wistar rats. Male and female rats were administered resveratrol 50 mg/L in the drinking water for 3 weeks. Dose-response curves for phenylephrine (10-9-10-4M) and acetylcholine (10-9-10-4M) were obtained in aortic rings from both female and male rats. Phenylephrine-induced maximum contraction (Emax) was decreased from 91.63±9.08 % (n=12) to 61.68±8.22 % (n=9); (P<0.05) and from 123.02±4.12 % (n=12) to 96.6±5.15 % (n=13); (P< 0.05) in female and male rat aortic rings, respectively. EC50 values (-log M) for control and resveratrol treated groups were 6.22±0.073 and 6.21±0.071 in male groups, respectively and 6.36±0.071 and 6.06±0.072 in female groups, respectively; (P< 0.05). Acetylcholine-induced maximum relaxation was significantly enhanced in aortic rings from male rats but not from female rats.Emax value for acetylcholine was 76.26±4.71% (n=10) in male control and 96.46±5.6 % (n=10) in resveratrol treated male rat aortic rings; (P<0.05). However, EC50 value for female rats was changed from 6.83±0.074 to 7.35±0.082 in resveratrol treated group(P< 0.01). In conclusion, the results suggest that oral administration of resveratrol decreased phenylephrine-induced contraction both in female and male rat groups however the maximum relaxation to acetylcholine increased in the male group while sensitivity to acetylcholine was increased in female group. The results of this study may have an important value in understanding the beneficial effects of red wine in cardiovascular system.

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