硝普钠对过氧化氢诱导增龄大鼠血小板活化影响

目的:探讨过氧化氢对增龄大鼠血小板活化及NO(nitric oxide)供体硝普钠,对过氧化氢诱导下血小板活化的影响。方法:使用8个月龄、13个月龄Wistar大鼠血小板悬浮液,测定一氧化氮(nitricoxide,NO)、环磷鸟苷(cGMP)含量、血管舒张因子刺激的磷酸蛋白(vasodilator-stimulated phosphoprotein,VASP)磷酸化以及活性氧族(reactive oxygen species,ROS)水平。结果:过氧化氢刺激血小板活化时,8个月龄、13个月龄大鼠的血小板NO含量均有降低,硝普钠以剂量依赖的方式增加了大鼠血小板内的NO含量,但2组之间差异无统计学意义;硝普钠能明显增强8个月龄大鼠过氧化氢刺激的血小板VASP磷酸化水平,但对13个月龄大鼠血小板的VASP磷酸化无明显影响;硝普钠明显增加了8个月龄大鼠细胞内cGMP含量,但对13个月龄大鼠cGMP的产生无明显影响;硝普钠对2组大鼠血小板ROS产生没有抑制作用。结论:硝普钠明显增加8个月龄大鼠过氧化氢刺激血小板的cGMP含量以及VASP磷酸化,但硝普钠对8个月龄和13个月龄大鼠血小板NO产生的影响差异无统计学意义。硝普钠对13个月龄大鼠血小板VASP磷酸化以及cGMP产生的影响较小。提示老龄机体血小板功能改变与cGMP活性下降、VASP磷酸化水平降低相关。这一结果为今后抗血栓药物研究提供了新的思路靶点。

Effect of SNP on platelet activation induced by H2O2 in aging rats

Objective：To investigate the effects of SNP on platelet activation induced by H2O2 in aging rats. Methods：Platelet suspension was prepared by using blood of 8month rats or 13month rats. Nitric oxide was measured by nitric oxide measurement kit. cGMP were detected by cGMP ELISA assay kit. VASP phosphorylation were analysed by Westren blotting. ROS generation was checked by flow cytometry. Results： The generation of NO was decreased in H2O2 activated platelets of 8 month rats or 13 month rats. SNP （sodium nitroprusside,SNP） increase the level of NO in a dose-dependent manner in both 8 month rats and 13 month rats,but there were no differences in the two groups. VASP phosphorylation was augmented by SNP treatment in 8 month rats platelets,but not 13 month rats. SNP enhanced cGMP level on activated platelets induced by H2O2,but there were not increase in 13 month rats. ROS were increased in H2O2 stimulated platelet in both 8 month rats and 13 month rats. However,SNP almost has no inhibiting effects on ROS generation in the two groups. Conclusion：SNP significantly increased the level of cGMP and VASP phophorylation in H2O2 induced platelet activation of 8 month rats. In contrast SNP had little effects on cGMP and VASP phophorylation in 13 month rats. There no difference on NO generation by SNP treated platelets in 8 month rats and 13 month rats. The results suggested that platelet function change in older rats was associated with decrease of cGMP and VASP phophorylation when platelet activation induced by H2O2.