新生小鼠缺氧缺血性脑损伤模型的建立

摘要

目的 对经典Vannucci法进行改进,建立一种简便、稳定的新生小鼠缺血缺氧脑损伤模型.方法 将新生11 d的KM小鼠分为正常对照组(N组,n=20)和缺血缺氧组(HIBD组,n=160),对HIBD组行左侧颈总动脉结扎,分别按照C1-C8条件缺氧建模.建模后通过比较各条件下小鼠死亡率、建模成功率和TTC染色脑梗死体积,选取最稳定的建模条件.建模后利用体重生长曲线分析小鼠生长发育情况;Longa、Grip test、悬吊试验评估小鼠神经运动功能;HE染色观察脑组织病理改变.结果 新生小鼠行左侧颈总动脉结扎,8%O2、35℃条件下缺氧45 min,死亡率低(8.3%)且成模率高(47.92%);HIBD组较N组小鼠体重增长缓慢并出现严重的神经运动功能障碍;结扎侧出现脑梗死区,约占全脑体积(17.76±0.70)%;结扎侧大脑皮层及海马区神经元出现变性坏死.结论 本实验采用新生小鼠行左侧颈总动脉结扎,在8%O2、35℃条件下缺氧45 min复制HIBD动物模型,简便且稳定性好,是用于新生儿缺血缺氧性脑损伤研究较为理想的动物模型.%Objective To improve the classic Vannucci method for establishing a model of hypoxic-ischemic brain damage in the neonatal mice. Methods Postnatal day 11 KM mice were randomly assigned into normal control group ( N group, n=20) and hypoxic-ischemic brain damage group (HIBD group, n=160). For the HIBD group, the left common carotid artery of mice was ligated and exposed to hypoxia according to different conditions in the groups C1-C8, then com-pared the mortality and the success rates of all groups. TTC staining and relative infarct volume was measured to select the most stable conditions of modeling. In all groups, the growth and development of mice were evaluated by body weight growth curve at different time points after modeling. Longa test, grip test and hanging test were porformed to assess the neu-romotor function. HE staining was used to detect cerebral neuronal pathological changes. Results Neonatal mouse models of hypoxic-ischemic brain damage were established by the left common carotid artery ligation and hypoxia for 45 min under conditions of 8% O2 and 35℃, which resulted a low mortality rate (8. 3%) and high success rate (47. 92%). Compared with the normal group, mice of the HIBD group grew slowly in body weight and showed severe motor dysfunction. The liga-tion side of cerebral artery showed infarction area which accounted for 7. 76 ± 0. 70% of the total brain. The cortex and hip-pocampus of ligated brain tissue showed neuron degeneration and necrosis. Conclusions The neonatal mouse model of hy-poxic-ischemic brain damage is successfully established by our modified method , i. e. to ligate the left common carotid ar-tery and to expose the mice to hypoxia at 8% O2 and 35℃ for 45 min. This model provides a liable and stable experimental animal model for research of neonatal hypoxic-ischemic brain damage.