Modulation of haemostatic function and prevention of experimental thrombosis by red wine in rats: a role for increased nitric oxide production

1 The effects of ethyl alcohol and wine (red and white) on haemostatic parameters and experimental thrombosis were studied in rats; NO was evaluated as a possible mediator of these effects. 2 We found that red wine (12% alcohol) supplementation (8.4 +/- 0.4 ml d(-1) in drinking water, for 10 days) induced a marked prolongation of 'template' bleeding time (BT) (258 +/- 13 vs 132 +/- 13 s in controls; P<0.001), a decrease in platelet adhesion to fibrillar collagen (11.6 +/- 1.0 vs 32.2 +/- 1.3%; P<0.01) and a reduction in thrombus weight (1.45 +/- 0.33 vs 3.27 +/- 0.39 mg; P<0.01). 3 Alcohol-free red wine showed an effect similar to red wine. In contrast, neither ethyl alcohol (12%) nor white wine (12% alcohol) affected these systems. 4 All these effects were also observed after red wine i.v. injection (1 ml kg(-1) of 1.4 dilution) 15 min before the experiments. 5 The effects of red wine were prevented by the NO inhibitor, N(omega)nitro-L-arginine-methyl ester (L-NAME). L-arginine, not D-arginine, reversed the effect of L-NAME on red wine infusion. 6 Red wine injection induced a 3 fold increase in total radical-trapping antioxidant parameter values of rat plasma with respect to controls, while white wine and alcohol did not show any effect. 7 Our study provides evidence that red wine modulates primary haemostasis and prevents experimental thrombosis in rats, independently of its alcohol content, by a NO-mediated mechanism.