Endothelial NO release caused by red wine polyphenols

Epidemiological studies have suggested that moderate consumption of red win e might reduce the risk of cardiovascular disease. Red Wine Polyphenolic Co mpounds (RWPC), a complex extract obtained from red wine, causes endotheliu m-dependent vasorelaxation in rat aortic rings pre-contracted with noradren aline. This effect is associated with marked formation of NO in the vessel (directly shown by electron paramagnetic resonance spectroscopy) and it is abolished by the NO synthase inhibitor NG-nitro-L-arginine methylester (300 mu M). It is mimicked by some defined polyphenols (like the anthocyanin de lphinidin) but not by others(malvidin, cyanidin, quercetin, catechin, epica techin), despite close structures. In addition, RWPC causes an extracellula r Ca2+-dependent increase in [Ca2+](i) in endothelial but not in smooth mus cle cells. The efficiency of RWPC in inducing NO production in the aorta an d increase in [Ca2+](i) in endothelial cells is comparable to those of carb achol and bradykinine, respectively. These findings provide evidence that R WPC and polyphenols with selective structures can activate an undefined tar get in endothelial cells. The resulting increase in [Ca2+](i) activation of NO-synthase and enhanced formation of NO may be involved in cardiovascular :protection.