线栓法大鼠大脑中动脉阻塞脑缺血—再灌注模型行为学特点及其与梗死体积关系分析

摘要

目的 分析线栓法大脑中动脉阻塞(MCAO)脑缺血—再灌注模型大鼠的行为学特点,及其与梗死体积的关系.方法 选择成年健康雄性SD大鼠108只,通过线栓法制作大脑中动脉阻塞后脑缺血—再灌注模型,阻塞100 min后拔除线栓再灌注,MCAO术后24h行核磁共振扫描明确梗死部位并计算梗死灶体积,依据是否存在梗死灶及梗死灶部位将大鼠分为:皮质及基底节梗死组(CBG组,n=53)、基底节梗死组(BG组,n=29)及无梗死组(NI组,n=26).应用Bederson评分、横木行走实验及足失误测试对大鼠MCAO术后24 h的神经功能损害程度进行评价,并分析3组大鼠行为学评分及其与梗死体积的相关性.结果 NI组、BG组的Bederson评分明显低于CBG组(q=4.56、4.32,P均＜0.01),而BG组及NI组评分差异无统计学意义(q=0.42,P=0.897);NI组、BG组的横木行走实验评分明显高于CBG组(q=4.22、3.98,P＜0.01),而BG组及NI组评分差异无统计学意义(q =0.24,P=0.101);NI组、BG组的足失误率明显低于CBG组(q=3.68、3.24,P＜0.05),而BG组及NI组足失误率差异无统计学意义(q =0.46,P=0.830).CBG组脑梗死体积明显大于BG组脑梗死体积,差异有统计学意义[(276.05±90.11)mm3 vs.(60.03 ±25.17)mm3,t=15.856,P＜0.01],大鼠Bederson评分、横木行走实验及足失误测试中的行为学评分与其梗死体积之间均无线性相关性(CBG组:r=-0.149、-0.231、-0.186,P=0.308、0.111、0.249;BG组:r =0.187、-0.332、0.291,P=0.381、0.113、0.168).结论 通过线栓法制作大鼠大脑中动脉阻塞脑缺血—再灌注模型可出现2种行为学表现差异显著的梗死类型,且各个类型的行为学评分与其梗死体积大小不呈正比.%Objective To analyze the behavioral characteristics of cerebral ischemia in rats after middle cerebral artery occlusion (MCAO) method by inserting a nylon filament and the relationship between behavioral performance and the infarct volume.Methods One hundred and eight male SD rats were used in this study.The MCA were blocked by a nylon filament and reperfusion after 100 minutes.To determine the site and the volume of infarction,MR scan were performed in each rat 24 hours after the surgery.The rats were divided to three groups that cortex basal ganglia infarction group (CBG,n =53),basal ganglia infarction group (BG,n =29) and non-infarction group (NI,n =26) according to the MRI scan results.The behavioral tests,including Bederson's scale,beam walking test,foot fault test were used to evaluate the neurologic deficits at the second day after the MCAO surgery.Results In the Bederson's scale,there was significant difference between NI and CBG (q =4.56,P ＜ 0.01),and this difference also existence between BG and CBG (q =4.32,P ＜ 0.01),but between NI and BG showed no difference (q =0.42,P =0.897).In the beam walking test,there was significant difference between NI and CBG (q =4.22,P ＜ 0.01),also between BG and CBG (q =3.98,P ＜ 0.01),but there is no difference between NI and BG (q =0.24,P =0.101).In the foot fault test,there was difference between NI and CBG (q =3.68,P ＜ 0.05),also between BG and CBG (q =3.24,P ＜ 0.05),but between NI and BG showed no difference (q =0.46,P =0.830).In the CBG and BG,there was no significant difference between performance of three behavioral tests (Bederson's scale,beam walking test,foot fault test) and the volume of infarction (CBG:r =-0.149,r =-0.231,r =-0.186,P =0.308,P =0.111,P=0.249;BG:r=0.187,r=-0.332,r=0.291,P=0.381,P=0.113,P=0.168).Conclusion The MCAO method in rats can appear two different infarction types,and the behavioral characteristics are very different.The behavioral characteristics in each infarction type are not proportional to the infarct volume.