局灶性脑缺血再灌注损伤后大鼠血脑屏障通透性的研究

Evaluation of blood-brain barrier permeability after cerebral ischemia/reperfusion in rats

【目的】探讨局灶性缺血再灌注损伤后早期大鼠血脑屏障(blood brain barrier,BBB)功能障碍的变化和水肿形成的规律。【方法】应用伊文思蓝法(Evans-Blue,EB)观察再灌注后不同时间点BBB通透性变化,采用干湿重法计算脑含水量评估脑水肿、TTC法评估脑梗死面积。【结果】脑缺血再灌注3 h时,大鼠BBB通透性明显增加(P<0.05),24 h最高(P<0.01);缺血再灌注各组缺血侧大脑半球EB含量与对侧相比差异有显著性(P<0.05)。与假手术组相比EB含量差异均有显著性(P<0.05)。脑含水量变化与BBB通透性改变呈平行关系;但缺血再灌注后各时间点梗死面积差异无显著性。【结论】缺血再灌注损伤早期,大鼠BBB完整性受到破坏,脑水肿加重,因此应将BBB的结构和功能稳定性作为缺血再灌注损伤早期治疗的关注重点。

[Objective] To explore change of blood brain barrier （BBB） and formation edema at early period after cerebral ischemia/reperfusion in rats. [Methods] Damage to the BBB was judged by extravasation of Evans Blue （EB） dye. Cerehral infarction volumes were quantitated by TTC staining and brain water content was determined By dry/wet weight method. [Results] At 3h of reperfusion after cerebral ischemia, the permeability of BBB began to increase（P〈 0.05） ,reached the peak at 24h of reperfusion （P〈0.01）. Comparing with normal side, the content of EB in the ischemia side were significant increased （P〈0.05）. As compared to sham-operated group, the concentration of EB in isehemiareperfusion groups was increased （P〈0.05）. The change pattern of brain water content was similar to that of EBB permeability. However, cerebral infarction sizes in ischemia-reperfusion groups were not significant difference. [Conclusion] Integrality of the BEE is broken down at early period of cerebral ischemia/reperfusion, and exacerbated cerebral edema.