Objectives: Increased blood pressure variability (BPV) is an independent risk factor for ischemic target organ damage.High BPV enhances oxidative stress, which can lead to platelets activation and might result in arterial thrombosis.The aim of this study was to investigate the influence of high BPV on arterial thrombosis in sinoaortic denervation rats.Methods: Rats were divided randomly into sham operation (Sham) group, sinoaortic denervation (SAD) group, SAD + hydrogen-rich saline (5 ml·kg-1.·d-1) group, SAD + hydrogen-rich saline (10 ml·kg-1·d-1) group and Vitamin C (250 ml·kg-1·d-1) group.Except the sham group, rats in other groups underwent SAD surgery.Four weeks after Sham or SAD operation, the animals were given intraperitoneally normal saline, hydrogen-rich saline or Vitamin C for 4 weeks.Hemodynamics was monitored in conscious, freely moving rats.Carotid artery thrombosis was induced by 30% ferric chloride.Time till occlusion was measured by Laser Doppler Flowmetry.ADP-induced platelet aggregation was measured with turbidimetric method.Platelet adhesion at low shear rate and high shear rate was tested in a perfusion chamber.Levels of nitric oxide (NO), reactive oxygen species (ROS) and Ca2+ in platelets were determined by flow cytometry.Results: When compared with the Sham group, there was no change in systolic blood pressure,diastolic blood pressure and mean blood pressure in SAD group, whereas systolic blood pressure variability, diastolic blood pressure variability and mean blood pressure variability increased significantly and baroreflex sensitivity decreased markedly in SAD group.Time till occlusion was significantly shorter, Also, platelet aggregation, platelets adhesion to collagen, the level of ROS and MDA in plasma and Ca2+ in platelets were significantly raised.However, the level of NO and SOD in plasma and NO in platelet were significantly reduced.When compared with the SAD group, time till occlusion in hydrogen-rich saline group and Vitamin C group was significantly prolonged.Platelet aggregation, adhesion, the level of ROS, MDA and Ca2+ were significantly reduced, whereas the level of NO and SOD in plasma and NO in platelets were significantly higher.Conclusion: Hydrogen-rich saline might improve arterial thrombosis in SAD rats through inhibition of platelet activation and oxidative stress.