亚低温对脑缺血再灌注后血脑屏障损伤及明胶酶活性的影响  

Effects of mild hypothermia on the blood-brain barrier and the activity of gelatinases following transient focal cerebral ischemia

作　　者：苏颖[1] 孙圣刚[1] 

机构地区：[1]华中科技大学同济医学院附属协和医院神经内科,湖北武汉430022

出　　处：《中国康复医学杂志》2007年第10期893-896,共4页Chinese Journal of Rehabilitation Medicine

摘　　要：目的:应用MRI动态监测亚低温对脑缺血再灌注后血脑屏障损伤的影响,并探讨其保护机制。方法:雄性Wistar大鼠42只,随机分为常温缺血组、亚低温缺血组和假手术组。线栓法建立大鼠大脑中动脉缺血再灌注模型,分别于再灌注3.5h、24h和5d行T1WI增强扫描,再灌注24h和5d进行大鼠神经功能缺损评分,脑组织明胶酶活性测定,以及明胶酶活性与磁共振表现的相关分析。结果:亚低温治疗明显减小了各时间点T1WI信号强化的范围和强度,显著降低缺血再灌注早期及晚期神经功能缺损评分和脑组织明胶酶活性。常温缺血组再灌注24h后MMP-9活性与T1WI信号强化范围正相关。结论:亚低温能明显减轻缺血再灌注后血脑屏障损伤的范围和程度,促进神经功能恢复,其保护机制可能与亚低温降低MMP-9、MMP-2的活性有关。Objective：To investigate the effects of mild hypothermia on the blood-brain barrier （BBB） injury after transient focal cerebral ischemia by means of magnetic resonance imaging, and explore the underlying mechanism. Method：Fourty two Wistar rats were randomly divided into the normothermic ischemic group, hypothermic ischemic group and sham-operated group. Middle cerebral artery occlusion （MCAO） was induced by the intraluminal suture method. Contrast enhanced Tl-weighted imaging was taken at 3.5h, 24h and 5d after reperfusion respectively. The neurological deficit scores were evaluated at 24h and 5d after reperfusion, and correspondingly, brain MMP-2 and MMP-9 activities were quantified by gelatin zymography. Correlation between MR findings and the activity of gelatinases was analyzed. Result：At all time points lesion volume and signal intensity on postcontrast T1WI were significantly reduced by hypothermia. Hypothermia improved neurological outcome and inhibited the activity of gelatineases during both the early and late phases of ischemia-reperfusion. The activity of MMP-9 at 24h after reperfusion showed significantly correlation with the enhanced volume on postcontrast T1WI. Conclusion：Mild hypothermia attenuates BBB disruption and improves neurological outcome after transient focal cerebral ischemia. Suppressing activities of MMP-2 and MMP-9 may be responsible for the vascular protection of hypothermia.

关 键 词：脑缺血 亚低温 血脑屏障 明胶酶 磁共振成像 

分 类 号：R743[医药卫生—神经病学与精神病学]