cNOS介导心肌缺血／再灌注损伤机制的研究

目的：通过研究心肌缺血/再灌注时结构型一氧化氮合酶（ constitutive nitric oxide synthase ，cNOS）活性的变化及cNOS活性与P38激活的关系，来揭示心肌缺血/再灌注损伤中cNOS所发挥的作用。方法实验分为假手术组、缺血/再灌注组、缺血给溶剂组和缺血给药组。采用NOS试剂盒检测cNOS活性，生物素转化法检测P38巯基亚硝基化，免疫印迹检测P38磷酸化水平。结果心肌缺血/再灌注时cNOS活性显著增加，同时P38巯基亚硝基化和磷酸化水平均显著升高。内皮型一氧化氮合酶（ endothelial nitric oxide synthase ，eNOS）和神经型一氧化氮合酶（ neuronal nitric oxide synthase ，nNOS）抑制剂则阻止缺血/再灌注引起的P38巯基亚硝基化和磷酸化水平升高。结论心肌缺血/再灌注中cNOS活性增强，大量产生的NO使P38巯基亚硝基化并活化，从而介导心肌凋亡。

The role of cNOS in myocardial ischemic reperfusion injury

Objectives To investigate the role of constitutive nitric oxide synthase （ cNOS） in myocardial ischemia/reperfusion injury through studying the changes in cNOS activity and its relationship with P 38 activation.Methods SD rats were divided into a control group , an ischemia/reperfusion group , a vehicle group and a treatment group .An NOS kit was used to examine cNOS activity .The biotin-switch method was adopted to examine P 38 S-nitrosylation, while Western blot to detect P 38 phosphorylation .Results cNOS activity was significantly increased during myocardial ische-mia/reperfusion .Meanwhile , the S -nitrosylation and phosphorylation of P 38 were also enhanced at the same time , which could be blocked by the inhibitors of eNOS and nNOS .Conclusion The activity of cNOS can be increased during myocardial ischemia/reperfusion injury , in which large quantities of NO make P 38 S-nitrosylated and activated , leading to myocardial apoptosis .