心肌缺血及再灌注大鼠血浆蛋白C活性变化的实验研究

Experimental study on the changes of protein C activity in plasma with myocardial ischemia and reperfusion in rats

目的:探讨心肌缺血及再灌时大鼠血浆蛋白C(PC)活性及血小板聚集率的变化和意义。方法:SD雄性大鼠40只,随机分为对照组(C,n=8)、缺血组(I,n=24)和缺血再灌组(IR,n=8),缺血组按照造模后缺血时间的不同又分别分为缺血10 min(I10)、30 min(I30)及60 min(I60)组,每组8只。采用可逆性阻断大鼠左冠状动脉前降支的方法制备心肌缺血及再灌注模型,实验结束后即刻颈总动脉取血,以发色底物法检测血浆蛋白C活性,比浊法测定血小板聚集率。结果:心肌缺血模型组大鼠血浆PC活性均明显低于对照组(P<0.01),且随心肌缺血时间延长降低;缺血再灌组PC活性略有恢复,但仍低于对照组(P<0.01)。血小板聚集率缺血10 min、缺血30 min组及IR组较对照组均明显升高(P<0.01),而缺血60 min组血小板聚集率与对照组比较无统计学意义。结论:心肌缺血及再灌注损伤可引起PC活性下降,PC活性的变化参与了心肌缺血及损伤的过程,较血小板聚集率敏感。因此,PC活性的变化有可能成为对评价缺血性心血管疾病有预报价值的指标。

AIM：To investigate the clinical significance of plasma levels of protein C（PC） and platelet aggregation in rats with myocardial ischemia and reperfusion injury. METHODS：40 male SD rats were randomly divided into groups of control（C,n=8）,ischemia（I,n=24） and ischemia-reperfusion（IR,n=8）.The ischemia groups were divided into 10 min（I10）,30 min（I30） and 60 min group（I60） respectively,8 rats in each group.The rat model of myocardial ischemia and reperfusion was prepared by the left anterior descending coronary artery reversible occlusion.Blood samples were collected from the carotid artery immediately.The plasma PC activity and platelet aggregation were detected by chromogenic substrate assay and turbidity assay,respectively.RESULTS：Plasma PC activities in myocardial ischemia rats were significantly lower than those in the control（P0.05）,and there is a negative relation between the decrease of PC activity and ischemia time;plasma PC activities in ischemia-reperfusion rats were slightly recovered,but still lower than those in the control（P0.01）.The platelet aggregation in ischemia 10 min,30 min ischemia and IR rats were significantly higher than those in the control（P0.01）,while ischemia 60 min platelet aggregation showed no statistical significance compared with the control group.CONCLUSION：Myocardial ischemia and reperfusion injury can result in PC activities loss.These suggest that the decrease of PC activity may be involved in myocardial ischemia and injury,more sensitive than platelet aggregation.Therefore,the PC activity maybe a predictive indicator for ischemic cardiovascular disease.