Objective To study the changes of SUR1-regulated NCCa-ATP channels in core area during focal cerebral ischemia and reperfusion in rats, and to explore the therapeutic window of focal cerebral ischemia. Methods Adult male Wistar rats were rendered to undergo 120 minutes of the left middle cerebral artery occlusion (MCAO) by the intraluminal thread technique before reperfusion. The core area of the left hemisphere cortex ischemia/reperfusion at different times (reperfusion:R3 h, 6 h, 8 h, 12 h and 24 h) was taken to be tested the level of mRNA and protein expression of sulfonylurea receptor 1 (SUR1) using RT-PCR and Western-blot techniques. SUR1 of the ischemic brain microvascular endothelial cells were observed by immunofluorescence double staining at the peak expressing time point of SUR1. Results We found the up-regulation of SUR1 mRNA and SUR1 protein in ischemic infarcts tissues for R3 h, 6 h, 8 h and 12 h, peaked at R8 h, compared with the sham-operation group ( <0.05) . However, SUR1 expression increased was observed at R12 h by double immunofluorescence in microvascular endothelium. Conclusion SUR1-regulated NCCa-ATP channel may take part in cerebral ischemic damage during focal cerebral ischemia and reperfusion. The expressions of SUR1 mRNA and SUR1 protein were up-regulated in ischemic infarcts tissues. The data suggested that the best time to apply SUR1 inhibitor is within 8-12 hours after ischemia and reperfusion.%目的：了解局灶性脑缺血再灌注后磺酰脲类受体1（SUR1）调控的非选择性阳离子通道（nonselective cation channel，NCCa-ATP通道）表达的变化与脑缺血损伤的关系，探索脑缺血的治疗时间窗．方法以颈内动脉线栓法建立大鼠大脑左侧中动脉梗塞模型，缺血2h后恢复再灌注．取实验性脑缺血再灌注损伤后3 h、6 h、8 h、12 h、24 h等不同时间缺血核心区的脑组织，采用RT-PCR及Western-blot技术，测定SUR1的mRNA及蛋白表达水平．采用免疫荧光双标法技术，观察SUR1在缺血后脑微血管内皮细胞的表达情况．结果缺血再灌注核心区组织在缺血再灌注后3 h、6 h、8 h、12 h及24 h各时间点SUR1 mRNA和SUR1蛋白的表达量均上调，再灌注后8 h达高峰（＜0.05），缺血再灌注后12 h，SUR1在脑微血管内皮细胞的表达非常明显．结论局灶性脑缺血再灌注过程中SUR1调节的NCCa-ATP通道参与了脑缺血损伤，在脑缺血再灌注后其mRNA和蛋白的表达量均上调．推测应用SUR1受体的特异性抑制剂最佳时机在缺血再灌注后8～12 h．
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