三七总皂苷对大鼠脑缺血再灌注后Caspase表达的影响

Effects of Panax Notoginseng Saponins on expression of Caspase after focal cerebral ischemia-reperfusion in rats

目的研究大鼠局灶性脑缺血再灌注后脑组织中天冬氨酸特异性半胱氨酸蛋白酶(Caspase-1、Caspase-3、Caspase-8)蛋白表达的变化,以及三七总皂苷(PNS)对其表达的影响。方法采用线栓法建立大鼠大脑中动脉栓塞局灶性脑缺血再灌注模型。实验动物随机分为假手术组、模型组、三七总皂苷组和尼莫地平对照组,于缺血前5 m in、缺血后12、24、36 h给药,共给药4次。缺血2 h再灌注46 h后,采用免疫组织化学方法检测脑组织中Caspase-1、Caspase-3、Caspase-8蛋白表达的变化。结果缺血2 h再灌注46 h后,可诱导脑组织Caspase-1、Caspase-3表达增强,PNS能下调Caspase-1、Caspase-3蛋白的表达;但对Caspase-8的表达无影响。结论PNS能抑制脑缺血再灌注后Caspase-1、Caspase-3蛋白的表达,这可能是其促进脑缺血后神经元存活及损伤后修复的机制之一。

Aim To investigate the effects of Panax Notoginseng Saponins （PNS） on expressions of Caspase-1, Caspase-3 and Caspase-8 after transient focal cerebral ischemia-reperfusion （ CIR ）. Methods CIR injury was induced by middle cerebral artery ocelusion （MCAO） in rats. The rats were treated with PNS（25 mg·kg^-1 ） and Nimodipine （ 1 mg·kg^-1 ）. The drugs were administered 5 min before cerebral isehemia, and 12,24 and 36 h after cerebral isehemia. Sham operation group and model group were given equal volume normal saline. The expressions of Caspase were observed by using immunochemistry after cerebral ischemia for 2 h followed by reperfusion for 46 hours. Results The expressions of Caspase-1 and Caspase-3 protein increased after cerebral ischemia. PNS decreased the expressions of Caspase-1 （P 〈 0.05） and Caspase-3 （ P 〈 0. 01 ） obviously compared with the model group. But PNS had no evident effect on the expression of Caspase-8 after CIR. Conclusion PNS can reduce the activation of Caspase-1 and Caspase-3 after CIR damage .