摘要
目的探讨缺血性卒中大鼠梗死灶中心和周围白质纤维束损伤情况。方法共25只Sprague-Dawley大鼠随机分为对照组(10只)和大脑中动脉闭塞组(MCAO组,15只),其中MCAO组以线拴法制备大脑中动脉闭塞模型。两组大鼠分别于模型制备后3 h、6 h、1 d、2 d、3 d、4 d和7 d,采用高场强(7.0T)扩散张量成像(DTI)和扩散张量纤维束示踪成像(DTT),于梗死侧皮质、皮质下和胼胝体选择兴趣区并计算部分各向异性(FA)值、平均扩散率(MD)值、轴向扩散系数(λ║)值和径向扩散系数(λ┴)值,以及于内囊区选择兴趣区并计数纤维数目(NT)值。结果两组大鼠不同时间点梗死侧皮质、皮质下和胼胝体FA值(均P=0.000)、MD值(均P=0.000)、λ║值(均P=0.000)和λ┴值(均P=0.000)差异均有统计学意义,MCAO组梗死侧皮质、皮质下和胼胝体FA值于超急性期(≤6 h)缓慢升高(均P=0.000)、急性期(6小时至3天)明显下降(均P=0.000)、亚急性期(3天至8周)趋于稳定,MD值、λ║值和λ┴值均于急性期明显升高(均P=0.000),亚急性期趋于稳定;对照组与MCAO组大鼠梗死侧皮质、皮质下和胼胝体FA值(P=0.003,0.000,0.000),皮质下MD值(P=0.013),皮质下和胼胝体λ║值(P=0.012,0.001)和λ┴值(P=0.001,0.036)差异有统计学意义。两组大鼠不同时间点梗死侧NT值差异有统计学意义(P=0.000),MCAO组梗死侧NT值于超急性期缓慢下降(P=0.032)、急性期明显下降(均P=0.000)、亚急性期趋于稳定;MCAO组大鼠各时间点梗死侧NT值低于对照组(P=0.000)。DTT显示,MCAO组大鼠梗死侧白质纤维束走行迂曲,部分离断,尤其模型制备1 d后即可见梗死侧受损纤维趋于围绕病灶边缘。结论缺血性卒中超急性期至急性期,神经损伤持续存在,至亚急性期出现神经纤维重塑。DTT显示梗死侧受损纤维趋于围绕病灶边缘,提示受损纤维包绕病灶的保护作用。
Objective To evaluate the damage of white matter fiber tracts in the center and periphery of infarcts in the model rats of ischemic stroke. Methods A total of 25 Sprague.Dawley（SD）rats were randomly divided into control group（N = 10） and middle cerebral artery occlusion（MCAO） group（N = 15）. MCAO model was established by occluding with suture. At 3 h, 6 h, 1 d, 2 d, 3 d, 4 d and 7 d after model establishment, perform diffusion tensor imaging（DTI） and diffusion tensor tractography（DTT） at high.field 7.0 T MRI, choose cortex, subcortex and corpus callosum of infarct side as regions of interest（ROIs） and calculate the values of fractional anisotropy（FA）, mean diffusion coefficient（MD）, radial diffusivity（λ║） and axial diffusivity（λ┴）, choose internal capsule as ROI and calculate number of tracts（NT）. Results At different time points, FA value（P = 0.000, for all）, MD value（P = 0.000, for all）, λvalue（P = 0.000, for all） and λ┴ value（P = 0.000, for all） in the cortex, subcortex and corpus callosum of infarct side had significant difference between 2 groups. As time extended, in MCAO group FA value in cortex, subcortex and corpus callosum of infarct side was slowly increased in superacute phase（≤ 6 h; P =0.000, for all）, obviously decreased in acute phase（6 h to 3 d; P = 0.000, for all） and kept stable in subacute phase（3 d to 8 weeks）. MD value, λ║ value and λ┴ value were obviously increased in acute phase（P =0.000, for all） and kept stable in subacute phase. FA value in cortex, subcortex and corpus callosum of infarct side（P = 0.003, 0.000, 0.000）, MD value in subcortex（P = 0.013）, λ║（P = 0.012, 0.001） and λ┴（P =0.001, 0.036） values in subcortex and corpus callosum had significant differences between 2 groups. At different time points, NT value of infarct side had significant difference between 2 groups（P = 0.000）. As time extended, NT value of infarct side in MCAO group was slowly decreased in s
出处
《中国现代神经疾病杂志》
CAS
北大核心
2018年第1期47-54,共8页
Chinese Journal of Contemporary Neurology and Neurosurgery
基金
天津市自然科学基金重点资助项目(项目编号:16JCZDJC36000)
天津市应用基础及前沿技术研究计划项目(项目编号:09JCYBJC11600)
天津医科大学科学基金资助项目(项目编号:2012KYM13)~~
关键词
动脉闭塞性疾病
大脑中动脉
磁共振成像
疾病模型
动物
Arterial occlusive diseases
Middle cerebral artery
Magnetic resonance imaging
Disease models, animal
