Uncovering the Vasorelaxant Effect Induced by Vale do Sao Francisco Red Wine: A Role for Nitric Oxide

The aim of this study was to investigate the mechanisms underlying the vasorelaxant effect induced by the polyphenolic compounds found in red wine from Vale do Sao Francisco. In phenylephrine (10 mu M) precontracted mesenteric artery rings, the red wine caused a concentration-dependent relaxation (maximum response to phenylephrine 10 mu M = 87.5% +/- 6.5%, n = 10). After endothelium removal, the vasorelaxant effect elicited by red wine was attenuated (28.4% +/- 4.9%, n = 10). In addition, the vasorelaxant effect induced by red wine in rings pretreated with 100 mu M of N(w)-nitro-l-arginine methyl ester and 10 mu M of 1H-[1,2,4] oxadiazolo-[4,3-a]-quinoxalin-1-one was attenuated (23.4% +/- 5.1%, n = 7 and 11.8% +/- 2.7%, n = 6, respectively). Pretreatment with atropine did not affect the vasorelaxant effect induced by red wine (81% +/- 3.9%, n = 6). Furthermore, in rabbit aortic endothelial cell line, red wine 100 and 300 mu g/mL caused concentration-dependent increases in nitric oxide levels (58 +/- 1; 82 +/- 7.9; Delta% of fluorescence, n = 5, respectively). In conclusion, we suggest that the alcohol free-lyophilized red wine induces an endothelium-dependent vasorelaxant effect due, at least in part, to a secondary increase in the concentration of nitric oxide and that this effect might be associated with phenolic compounds found in the red wine.