最佳线栓头端直径建立对小鼠脑缺血再灌注模型成功率的影响

关键词：线栓法  线栓头端直径  脑梗死  大脑中动脉阻塞  磁共振血管成像  T2加权成像

Keywords:Zea-Longa method  diameter of the suture  the middle cerebral artery occlusion  MRA  T2WI

摘要：

      摘要 目的：改良的Zea-Longa线栓法建立小鼠（25—30g）脑缺血再灌注模型，以确定最佳线栓头端直径。 方法：将140只健康雄性C57BL/6J、体重25—30g小鼠，随机分为假手术组和模型组，模型组再根据线栓头端直径大小分为0.24mm组，0.25mm组，0.26mm组，0.27mm组，0.28mm组及0.29mm组,每组各20只小鼠。采用头端直径不同大小的线栓制作右侧大脑中动脉阻塞再灌注模型。缺血1h后，进行脑多普勒血流检测、核磁共振血管成像及T2加权成像（T2WI），恢复血流灌注24h后进行神经行为学评分及TTC染色，明确最佳线栓头端直径建立脑缺血再灌注模型。 结果：与假手术组相比，体重25—30g小鼠，线栓头端直径在0.25mm—0.28mm之间都可以形成梗死灶。与其他组相比，线栓头端直径为0.26mm，Longa评分在1—3分最多、梗死面积最大（0.26mm vs 0.24mm、0.25mm、0.28mm、0.29mm P<0.0001）；线栓头端直径小于0.24mm或大于0.29mm，都不能形成梗死。多普勒血流仪检测、核磁共振血管成像及T2加权成像（T2WI）显示，与假手术组相比，0.26mm组线栓头端能够完全堵塞大脑中动脉血流，损伤侧血运与对侧相比，血运降至0，成功建立脑梗死模型。 结论：小鼠局灶性脑缺血再灌注模型的成功率与线栓头端直径大小密切相关，体重为25—30g小鼠用直径为0.26mm的线栓成功率最高。

Abstract:

      Abstract Objective: To determine the optimal tip diameter of the suture, we established the model of cerebral ischemia reperfusion in mice (25—30g) by the improved zea-longa method. Method: One hundred and forty healthy male mice(C57BL/6J, 25—30g) were randomly divided into the sham operation group and the experimental group. According to the tip diameter of the suture, the mice in the experimental group were divided into the 0.24mm group, 0.25mm group, 0.26mm group, 0.27mm group, 0.28mm group and 0.29mm group; and each group has 20 mice respectively. The model of right middle cerebral artery occlusion(MCAO) and reperfusion was made by using a different tip diameter of the suture. Transcranial Doppler(TCD),magnetic resonance angiography (MRA) and T2 weighted imaging (T2WI) were performed for each mouse 1h after ischemia. Neurobehavioral score and TTC staining were measured 24h after the reperfusion. Result: The area of infarct was formed between 0.25mm and 0.28mm in diameter at the end of the round bolt. Compared with other groups, the 0.26 mm group had the most mice with a Longa score between 1—3, and the biggest infarction area (0.26 mm vs. 0.24 mm, 0.25 mm, 0.28 mm, 0.29 mm (P<0.0001); In the groups using a tip diameter of the suture less than 0.24mm or more than 0.29mm, the infarction area was not formed. DCT, MRA and T2WI results showed that, rather than the sham operation group, the middle cerebral artery blood flow could be completely blocked, and the blood flow was reduced to 0 compared with the ipsilateral area with the tip of the 0.26mm; that is, the cerebral infarction model was successfully established. Conclusion: The success rate of middle cerebral artery occlusion is firmly related to the tip diameter of the suture. The diameter of 0.26mm tip of the suture is the best choice for middle cerebral artery occlusion in mice with a body weight of 25—30g.