The Phytoestrogen Genistein Produces Acute Nitric Oxide–Dependent Dilation of Human Forearm Vasculature With Similar Potency to 17β-Estradiol

• DOI: 10.1161/01.cir.103.2.258
• Publication Date: 2012-06-12T00:09:32Z
• Authors: H. A. Walker; T. S. Dean; T. A. B. Sanders; G. Jackson; J. M. Ritter; P. J. Chowienczyk
• Keywords: Brachial artery

Background —Genistein, a phytoestrogen, may have estrogenic cardioprotective actions. We investigated whether genistein influences endothelium-dependent vasodilation in forearm vasculature of healthy human subjects and compared the effects with those 17β-estradiol. Methods Results —The brachial arterial was cannulated 27-gauge needle for drug infusion. Forearm blood flow responses were measured strain-gauge plethysmography. Genistein (10 to 300 nmol/min, each dose 6 minutes) produced dose-dependent increase from 3.4±0.3 9.6±1.3 mL · min −1 100 (mean±SEM) men (n=9, P <0.0001 by ANOVA). The mean venous concentration during infusion highest 1.8±0.3 μmol/L additional men. similar premenopausal women. Daidzein, another ineffective, but equimolar concentrations 17β-estradiol caused genistein. Responses inhibited same degree NO synthase inhibitor N G -monomethyl- l -arginine. A threshold potentiated vasodilator acetylcholine not endothelium-independent nitroprusside. Conclusions —Genistein causes -arginine/NO-dependent potency potentiates acetylcholine.