二氮嗪预处理对大鼠脑缺血／再灌注损伤后血脑屏障的保护作用研究  

Research on the protective effect of diazoxide pretreatment on the blood-brain barrier of rats after cerebral ischemia/reperfusion injury

作　　者：何平平[1] 张鸿[1] 韩冬[1] 司味鑫 赵越[1] 李春瑶[1] 

机构地区：[1]中国医科大学附属盛京医院神经内科,沈阳110004

出　　处：《中国医师杂志》2016年第9期1309-1312,共4页Journal of Chinese Physician

基　　金：辽宁省科学技术计划项目（2012225069）;沈阳市科学技术计划（F12-277-1-02）;辽宁省“百千万人才工程”资助项目（2011921041）

摘　　要：目的研究二氮嗪预处理对大鼠脑缺血／再灌注损伤后血脑屏障的保护作用及机制。方法60只Wistar大鼠按随机数字表法分为假手术组、缺血再灌注组以及二氮嗪低、中、高剂量（5、10、20mg／kg）预处理组，采用线栓法制备大鼠大脑中动脉缺血再灌注模型。应用伊文氏蓝（EB）评估各组大鼠血脑屏障的通透情况，透射电镜观察各组大鼠血脑屏障的超微结构，采用免疫组织化学法检测各组大鼠的水通道蛋白-4（AQP4）的表达。结果（1）与假手术组相比，缺血再灌注组EB的渗透程度明显增加，中、高剂量二氮嗪预处理组EB的渗透程度明显减少，而低剂量处理组无明显变化；（2）透射电镜下，缺血再灌注组血脑屏障紧密连接开放，中、高剂量二氮嗪预处理组紧密连接重新呈现闭合状态，而低剂量处理组无明显变化；（3）与假手术组相比，缺血再灌注组AQP4蛋白表达明显增加（P〈0．01），与缺血再灌注组相比，中、高剂量二氮嗪预处理组AQP4蛋白表达显著降低（P〈0．01），而低剂量处理组无明显变化。结论中、高剂量二氮嗪预处理能够减轻大鼠脑缺血再灌注后的血脑屏障的破坏，其机制可能与维护血脑屏障紧密连接闭合状态、降低AQP4的表达有关。Objective To investigate the effect and its mechanism of diazoxide on the blood-brain barrier （BBB） of rats after cerebral ischemia/reperfusion （I/R） injury. Methods Sixty Wistar rats were randomly divided into sham operation group, I/R group, and diazoxide pretreatment groups of low, middle, large dose （5, 10, 20 mg/kg）. The I/R models of rats were performed to undergo middle cerebral artery embolism by thread. BBB permeability was estimated by Evans blue （EB） dyeing, transmission electron microscope （TEM） was used to observe the modification of interendothelial tight junction （TJ） of capillar- ies. The expression of aquaporin-4 （AQP4） in every rat brain tissues was detected by immunity histochem- istry technique. Results （1） Compared to sham operation group, the permeability extent of EB were signifi- cantly increased by I/R, which was distinctly attenuated in middle and large dose of diazoxide pretreatment rats, while no obvious changes were found between I/R and low dose groups. （2） TEM showed that TJ of the brain tissue opened after I/R injury and no significant opening of TJ was observed in middle and large dose of diazoxide preconditioning groups. （3） Compared to sham operation group,, the expression of AQP4 in the brain tissue of the I/R group was apparently increased （ P 〈 0. 01 ）. Compared to I/R group, the expres- sion of AQP4 was apparently increased in middle and large dose pretreatment groups （ P 〈 0. 01 ）, and there were no obvious difference between low dose group and the I/R group. Conclusions Preconditioning of ischemia/reperfusion injury with diazoxide protects the blood-brain barrier, which may due to keep the TJ closed and decrease expression of AQP4 protein.

关 键 词：二氮嗪/药理学 缺血预处理 脑缺血 再灌注损伤/药物疗法 血脑屏障/药物作用 

分 类 号：R743.3[医药卫生—神经病学与精神病学]