一种C57BL/6小鼠的dMCAO模型建立及评估

Establishment and evaluation of DMCAO model in C57BL/6 mice

目的:运用电凝法制备C57BL/6小鼠远端大脑中动脉闭塞(Distal middle cerebral artery occlusion,dMCAO)模型,完善急性缺血性脑卒中(Stroke)的小鼠模型方案。方法:54只雄性8~10周龄的C57BL/6小鼠,随机数字表法分为正常组6只,假手术组6只,dMCAO模型组42只。造模采用双电凝一侧大脑中动脉皮层支,同时结扎同侧颈总动脉。评估小鼠造模3 d、7 d存活率与7 d造模成功率;造模7 d采用2,3,5-三苯基四唑氮(Triphenyltetrazolium Chloride,TTC)染色评估脑梗死体积占比、激光微循环血流成像仪评估脑血流情况;造模3 d、7 d转棒实验评估小鼠运动协调能力。结果:3 d和7 d正常组与假手术组存活率100%,dMCAO模型组3 d和7 d平均存活率分别为83.35%、78.43%,dMCAO模型组造模成功率为66.7%;通过TTC染色评估模型小鼠梗死体积,正常组与假手术组梗死体积占比为0%,dMCAO模型组(6只)梗死体积占比为(18.22±0.89)%,95%可信区间(17.28,19.15)%。通过激光微循环血流成像仪评估模型小鼠脑血流,正常组与假手术组两侧脑血流占比之间差异无统计学意义。dMCAO模型组(6只)梗死侧脑血流较对侧降低占比(53.85±1.22)%,95%可信区间(52.57,55.13)%;通过转棒实验的在棒时间评估模型小鼠3 d和7 d运动能力,正常组与假手术组3 d、7 d在棒时间差异无统计学意义,dMCAO模型组(6只)与假手术组相比明显降低,差异有统计学意义(P<0.05)。结论:通过双电凝一侧大脑中动脉同时结扎同侧颈总动脉可以建立可靠的C57BL/6小鼠dMCAO模型。

Objective:to establish the model of distal middle cerebral artery occlusion(Distal middle cerebral artery occlusion,dMCAO)in C57BL/6 mice by electrocoagulation and to improve the mouse model of acute ischemic stroke(Stroke).Methods:54 male C57BL/6 mice aged 8-10 weeks were randomly divided into normal group(n=6),sham operation group(n=6)and dMCAO model group(n=42).The model was established by double electrocoagulation of one side of the cortical branch of the middle cerebral artery and ligation of the ipsilateral common carotid artery.The survival rate of 3 days and 7 days and the success rate of 7 days were evaluated;the proportion of cerebral infarction volume was evaluated by TTC staining on 7 days;the cerebral blood flow was evaluated by laser microcirculation blood flow imaging;and the motor coordination ability of mice was evaluated by rotating stick test on 3 days and 7 days.Results:the 3-day and 7-day survival rate of normal group and sham operation group was 100%.The average survival rate of 3-day and 7-day model group was 83.35%,78.43%and 66.7%,respectively.The infarct volume of model mice was evaluated by TTC staining.The proportion of infarct volume in normal group and sham operation group was 0%.The proportion of infarct volume in MCAO model group was(18.22±0.89)%,and the confidence interval of 95%was(17.28,19.15)%.The cerebral blood flow of model mice was evaluated by laser microcirculation blood flow imager.there was no significant difference in the proportion of bilateral cerebral blood flow between the normal group and the sham operation group.In the dMCAO model group,the infarcted cerebral blood flow decreased by(53.85±1.22)%and 95%confidence interval(52.57,55.13)%compared with the contralateral cerebral blood flow in the dMCAO model group(n=6).The motor ability of the model mice was evaluated by the stick time in the stick test,there was no significant difference between the normal group and the sham operation group,but there was significant difference between the dMCAO model group(n=6)and the sham operation group.Conclusion:the reliable dMCAO model of C57BL/6 mice can be established by double electrocoagulation of unilateral middle cerebral artery and ligation of ipsilateral common carotid artery.