不同线栓法脑缺血模型对小鼠脑区及行为的影响

Effects of different suture⁃occluded models of cerebral ischemia on brain regions and behaviors in mice

目的 探讨3种线栓法模型对小鼠不同脑区缺血及小鼠行为学差异的影响。方法 将120只ICR小鼠随机分成4组:假手术组、A组(颈总动脉进线栓至颈内动脉8 mm)、B组(颈外动脉进线栓至颈内动脉10 mm)、C组(颈总动脉进线栓至颈内动脉10 mm),每组30只。脑缺血1.5 h再灌注24 h后,采用2,3,5-氯化三苯基四氮唑(TTC)染色观察小鼠脑缺血部位并计算缺血面积,通过Longa评分评估小鼠神经运动功能,通过抓力实验评估小鼠的前肢力量,通过游泳实验评估小鼠的体力,伊文思蓝染色测定血脑屏障的通透性,通过计算脑含水量评估脑水肿程度,苏木精-伊红(HE)染色观察脑组织病理改变。结果 TTC染色结果显示3种方法造成小鼠大脑梗死的区域及面积有所不同,A、B组在梗死面积上差异无统计学意义(P>0.05),但C组梗死面积相较于A、B组差异均有统计学意义(P<0.05),假手术组未发现梗死区域。行为学实验结果显示A、B、C 3组结果相比于假手术组差异均有统计学意义(P<0.05),Longa评分中B、C组得分差异无统计学意义(P>0.05),但A组相较于B、C组差异均有统计学意义(P<0.05);前肢抓力实验中仅A、C组测试结果差异有统计学意义(P<0.05);游泳实验B、C组游泳时间差异无统计学意义(P>0.05),但A组相较于B、C组差异均有统计学意义(P<0.05)。伊文思蓝染色、脑含水量以及HE染色发现相比于A、B组,C组所造成的脑缺血对小鼠脑损伤更严重。结论 3种线栓法脑缺血模型造成小鼠大脑不同脑区的缺血,且小鼠皮质缺血更容易造成运动功能障碍。

Objective To explore the differences of brain regions and behaviors in cerebral ischemia mouse models caused by 3 suture-occluded models.Methods A total of 120 ICR mice were randomly divided into 4 groups:sham operation group,method A group(common carotid artery to internal carotid artery 8 mm),method B group(external carotid artery to internal carotid artery 10 mm),and method C group(common carotid artery to internal carotid artery 10 mm),with 30 mice in each group.After 1.5 h of cerebral ischemia and 24 of reperfusion,mice were stained with 2,3,5-triphenyltetrazolium chloride(TTC)to observe the site of cerebral ischemia and to calculate the area of ischemia.The neuromotor function of the mice was evaluated by the Longa score.The strength of the forelimb was measured by the grip test.The stamina of the mice was evaluated by the swimming test.The permeability of the blood-brain barrier was determined by the Evans blue staining.The cerebral edema was evaluated by the calculation of brain water content.Pathological changes of brain tissues were observed by hematoxylin-eosin(H-E)staining.Results TTC staining showed different sites and areas of cerebral infarcts caused by the 3 methods in mice.No significant difference was found in the infarct area between groups A and B(P>0.05),but the infarct area of method C was significantly different from that of groups A and B(all P<0.05).No infarct was detected in the sham operation group.The results of behavioral experiments of A,B,and C groups were significantly different from those of the sham operation group(all P<0.05).No significant difference was found in the Longa score between B and C groups(P>0.05),but the Longa score in A group was significantly different from that in B and C groups(both P<0.05).There was significant difference in the result of forelimb grip strength experiment between method A and C groups(P<0.05).No significant difference was found in the swimming time between B and C groups(P>0.05),but the swimming time in A group was significantly different from that in B and C groups(both P<0.05).The results of Evans blue staining,brain water content testing,and H-E staining revealed that cerebral ischemia caused by method C resulted in more severe brain damage in mice compared with methods A and B.Conclusion The 3 suture-occluded models can cause ischemia in different brain regions of cerebral ischemia mouse models,and ischemia in the cortex is more likely to cause motor dysfunction.