大鼠永久性脑缺血及缺血再灌注后半暗带caspase-3 mRNA表达变化

Changes of Caspase-3 mRNA Expression in the Regions after Permanent Ischemia and Ischemia-Reperfusion in the Rats Penumbra

目的 研究大鼠永久性脑缺血及缺血再灌注半暗带caspase 3转录水平表达规律。 方法 用插线法建立大鼠局灶性脑缺血及再灌注模型 ,剥取缺血半暗带及中心区皮质组织 ,采用半定量逆转录 -聚合酶链式反应(RT PCR) ,测定永久性缺血和缺血 1.5h再灌注各时间段caspase 3mRNA水平的变化。 结果 永久性缺血组皮质半暗带在缺血 8hcaspase 3mRNA开始升高 ,2 4h达到峰值 ,1周恢复正常水平。缺血中心区早期caspase 3mRNA无明显变化 ,缺血 2 4h时低于正常。再灌注组半暗带缺血后 8h后升高 ,16h达到高峰并持续至 2 4h。再灌注组caspase 3mRNA峰值高于永久缺血组 ,两者具有显著性差异。 结论 局灶性脑缺血半暗带caspase 3mRNA上调 ,再灌注可诱导caspase

Purpose: To investigate the changes of caspase-3 transcription level indifferent ischemic and reperfusion time in rats' ischemic penumbra. Methods: Focal ischemia models of middle cerebral artery occlusion (MCAO) were achieved by inserting nylon surgical thread through the internal carotid artery (ICA) into the anterior cerebral artery (ACA). After 1.5 h of left MCA occlusion, the thread was removed to allow reperfusion. Brain samples were harvested from ischemic penumbra and core of cortices. The expression of caspasee 3 mRNA was assessed by RT-PCR. Results: In the penumbra regions of premanent ischemia group, caspase-3 mRNA increased at 8 h post-MCAO and peaked at 24 h. In the ischemic core regions, caspase-3 mRNA failed to show significant changes at early stage and declined at 24 h. As for reperfusion group, caspase-3 mRNA was elevated at 8 h in penumbra cortices. It peaked at 16 h and continued to 24 h post-MCAO. The peak expression of caspase-3 in reperfusion group was higher than that in permanent ischemia group and hadstatistically significant between them. Conclusions: Caspase-3 mRNA was notably up-regulated in the penumbra regions after focal cerebral ischemia. Reperfusion may induce caspase-3 mRNA expression.