白藜芦醇抑制麻醉大鼠颈动脉窦压力感受性反射

摘要

目的 研究白藜芦醇的心血管保护作用是否与其对颈动脉窦压力感受器的作用有关.方法 隔离灌流麻醉大鼠颈动脉窦区,同时记录动脉血压的变化,并绘制压力感受性反射的功能曲线.结果 白藜芦醇(30, 60和120 μmol·L-1) 隔离灌流颈动脉窦区,压力感受性反射机能曲线向右上方移位,曲线的最大斜率下降,反射性血压下降的幅度降低,阈压增加,其变化呈浓度依赖性.预先应用NO合酶抑制剂 L-NAME 100 μmol·L-1或钙通道开放剂Bay K8644 500 nmol·L-1可消除白藜芦醇对压力感受器的抑制作用.用酪氨酸磷酸酶抑制剂正钒酸钠1 mmol·L-1预处理对白藜芦醇抑制压力感受性反射的作用无影响.结论 白藜芦醇对大鼠颈动脉窦压力感受器反射有抑制作用,此作用可能与局部NO的释放及减弱牵张敏感性通道的钙离子内流有关.%AIM To study the relationship between cardioprotective effects of resveratrol and carotid sinus baroreflex (CSB). METHODS The functional curve of the CSB was measured by recording changes in arterial pressure in anesthetized male rats with perfused isolated carotid sinus. RESULTS Resveratrol (30, 60 and 120 μmol·L-1) inhibited the CSB, which shifted the functional curve of the baroreflex to the right and upward. There were a marked decrease in peak slope and a reflex decrease of blood pressure, and also an increase in threshold pressure. Changes of these parameters showed a concentration-dependent manner. Pretreatment with Nω-nitro-L-arginine methylester (100 μmol·L-1), an inhibitor of nitric oxide synthase, and pretreatment with Bay K8644 (500 nmol·L-1), an agonist of L-type calcium channel, could both eliminate the inhibitory effect of resveratrol on CSB. A potent inhibitor of tyrosine phosphatase sodium orthovanadate (1 mmol·L-1) did not influence the effect of resveratrol on CSB. CONCLUSION Resveratrol inhibits carotid baroreflex, which may be mediated by the locally released NO and decreased calcium influx.