摘要
目的:观察L-硝基-精氨酸甲酯(L-NAME)对大鼠脑缺血再灌注损伤后血脑屏障功能和MMP-9表达的影响,探讨其对脑缺血再灌注损伤的保护作用及其机制。方法:将60只SD大鼠随机分为3组:1假手术组;2对照组;3L-NAME治疗组。用线栓法制作大鼠脑缺血再灌注模型,再灌注48h后干湿重法测定缺血脑组织含水量,用伊文思蓝测定血脑屏障通透性,免疫组织化学技术检测MMP-9的表达,同时电镜观察血脑屏障的变化。结果:脑缺血再灌注48h,对照组缺血侧脑含水量明显升高,EB含量也明显增加,电镜观察发现血脑屏障破坏严重,MMP-9的表达也较假手术组显著增加;而应用L-NAME处理的大鼠其缺血脑组织含水量明显减少,缺血侧EB含量较对照组也明显降低(P<0.05),同时电镜观察到血脑屏障的破坏减轻,而MMP-9表达水平也明显低于对照组。结论:L-NAME对大鼠脑缺血再灌注损伤后的血脑屏障具有保护作用,其作用机制可能是通过抑制MMP-9表达来实现的。
Objective： To investigate the effects of L-NAME on blood-brain barrier of cerebral ischemia and reperfusion in rats,and explore the possible mechanisms. Methods： 60 normal male SD rats were divided randomly into 3 groups：（1）Sham-operation （n = 20）; （2）Control （n= 20）;（3）L-NAME （n = 20）. Rat cerebral ischemia and reperfusion model was established by the method of thread inserting right middle cerebral artery occlusion（MCAO）, The brain water content was measured 48 h after reperfusion. At the same time,The permeability of blood-brain barrier was observed with electron microscope and by detecting the content of Evans Blue leaked out the brain tissue of ischemic side. The expression of MMP-9 in different groups was dtected by immunohistochemical method. Results： 48 h after crebral ischemia and reperfusion injuriy, the content of brain water and Evans Blue leaked out increased obviously, The breakdown of blood-brain barrier was severe the expression of MMP-9 also increased obviously. However, L-NAME can subtract the content of brain edema and Evans blue（P〈0.05）, relieve the breakdowm of blood-brain barrier on electron microscope. The expression of MMP-9 were decreased in L-NAME group contrasted with control group（P〈0.05）. Conclution： L-NAME has the protective effects on BBB in the model of cerebral ischemia and reperfusion injury. The mechanisms may be by restrainning the expression of MMP-9.
出处
《陕西医学杂志》
CAS
2009年第5期537-540,共4页
Shaanxi Medical Journal
