Dietary antioxidants are thought to be beneficial in reducing the incidence of coronary heart disease VSports手机版. In this study, the antithrombogenic endothelial cells (EC) defense was investigated in an experiment model in which cultured endothelial cells were incubated with aggregating platelets in the aggregometer. We examined the possible protective effect of trans-resveratrol (RSV) on oxidized low density lipoprotein (ox-LDL)-induced insults on the antithrombogenic activity of the vascular EC. EC were treated with ox-LDL (25-100 microg/ml) for 1 h with or without a 30 min-preexposure to RSV. The antiplatelet property of the endothelial cells was then shown by measuring platelet aggregation, [Ca2+]i and cGMP contents in the platelets and EC. Exposure of EC to ox-LDL reduced the antiplatelet aggregating property of EC, and this effect was attenuated by pretreatment with RSV. Further studies revealed that exposure of EC to ox-LDL reduced the protein contents of endothelial nitric oxide synthase (NOS). The effect of ox-LDL on the NOS protein content was abrogated by pretreating EC with RSV. The results suggest that ox-LDL acts via reducing the endothelial NOS activity to suppress the antithrombogenic activity of the EC. .