线栓法制备不同体重KM小鼠局灶性脑缺血／再灌注模型的建立及评价

Establishment and evaluation of a model of focal cerebral ischemia/reperfusion induced by monofilament in differently weighing Kunming mice

目的线栓法制备小鼠脑缺血/再灌注模型,并探讨影响该模型稳定性的因素。方法 KM小鼠100只,雌雄各半,体重20～39 g,分别将雌雄KM小鼠随机分为假手术组(n=20)和不同体重实验组(n=80)。其中实验组按小鼠体重分为以下8组:A组(♂,20～24 g)、B组(♂,25～29 g)、C组(♂,30～34 g)、D组(♂,35～39g),E组(♀,20～24 g)、F组(♀,25～29 g)、G组(♀,30～34 g)、H组(♀,35～39 g),每组10只。线栓栓塞法制备局灶性脑缺血/再灌注模型,选用单丝尼龙线(直径0.128～0.180 mm),液体石蜡处理浸泡后,从右侧颈总动脉进线,阻塞大脑中动脉血流,再灌注时拔出线栓,并对模型进行评价,采用的主要观察指标是神经功能损伤评分和2,3,5-三苯基氯化四氮唑(TTC)染色。结果同假手术相比,不同体重实验组小鼠脑缺血再灌注后,出现神经行为功能异常,TTC染色脑组织显示出明显的梗塞灶。与C、D组相比,A、B两组行为学评分以及梗死灶体积显著性增加(P<0.01);与G、H组相比,E、F两组的行为学评分以及梗死灶体积也显著性增加(P<0.01,P<0.05)。雄性KM小鼠与雌性相比,成模率较高且死亡率相对较低。此外,A组与E组相比,其行为学评分显著增加(P<0.01);B组与F组相比,小鼠行为学评分以及脑梗塞体积显著增加(P<0.01)。结论体重在25 g左右的雄性KM小鼠制备模型成功率较高,死亡率较低,适合建立小鼠局灶性脑缺血/再灌注模型。

Objective To establish a mouse model of focal cerebra! ischemia/repedusion with arterial monofila- ment insertion method, and explore the factors affecting the stability of this middle cerebral artery occlusion （MCAO） mod- eling procedure. Methods One hundred Kunming mice, weighing 20 - 40 g, male/female 1 ： 1, were randomly divided in- to 10 groups according to the body weight： sham group （ ♂ ）, sham group （ ♂ ）, group A （ ♂ , 20 -24 g）, group B （ ♂ , 25-29 g）, group C （ ♂, 30-34 g）, group D （ ♂ , 35-39 g）, group E （ ♀ ,20-24 g）, group F （ ♀, 25 -29 g）, groupG （♀, 30 -34g）, and groupH （♀, 35 - 39 g） ,10 mice in each group. Nylon thread （φ0.128-0.180 ram） was plugged into the internal carotid artery in mice to occlude the right middle cerebral artery reversibly. The reliability ofthe MCAO modeling method was evaluated by the degree of neurological deficit scores and 2,3,5-triphenyltctrazolium chlo- ride （TTC） staining. Results All groups except the sham groups presented changes in nearobehavioral function and dis- tinct infarction area in TTC staining after cerebral ischemic reperfusion. There were significant increases of behavioral scores and infarct volumes in the groups A and C （p 〈 0.01 ） , compared with that in the grmlps C and D. The neurological deficit scores in the groups E and F were markedly higher than that in the gr6ups G and H （ P 〈 0. 01 ）. Meanwhile, the volume of cerebral infarction was significantly inereased in the groups E and F in comparison with that in the groups G and H （P 〈 0.05）. Compared with the female mice, the success rates of MCAO models were higher in male mice while the mortality rates were lower. The neurological scores in the group A were significantly higher than that in the group E （ P 〈 0. 01 ）. In addition, there were significant increases of behavioral score and infarct volume in the group B （ P 〈 0. 01 ） , compared with that in the group F. Conclusions The establishment method of mouse model of focal cerebral ischemic/ reperfusion with arterial nylon monofilament insertion is stable and simple. However, there are many key factors affecting the success of this method, such as appropriately matching the mouse body weight with the nylon monofilament diameter, the mouse strain and gender selection, depth of thread insertion, operation time, and suitable temperature （ ca. 26℃ ） dur- ing experiment. Experimental investigation shows that male Kunming mice weighing about 25 g are most suitable for making focal cerebral ischemic/reperfusion models and serve relevant researches.