透光法测定小鼠局灶性脑缺血梗死灶

Light transmission measurement of focal ischemic cerebral infarction in mice

目的 :探索透光法评价局灶性脑缺血模型梗死体积的方法。方法 :采用大脑中动脉阻塞法 (MCAO)诱导小鼠持续性局灶性脑缺血 ,于缺血后 2 4 h取脑 ,切成 1mm厚的脑片 ,先在体视显微镜下进行透光 ,图像输入计算机 ;然后 ,在 0 .5 %氯化三苯四氮唑 (TTC)溶液中 37℃孵育 30 min,并将 TTC染色的脑片图像输入计算机。以 Ana-ly Power1.0软件计算每一脑片以透光法和 TTC染色法测得的梗死体积 ,以 Photoshop5 .0计算缺血组和对照组透光和 TTC染色脑片左右侧灰度。结果 :透光测定的脑梗死体积与 TTC染色测定的梗死体积具有较好的相关性(r=0 .81)。缺血组小鼠透光和 TTC染色测得的缺血侧大脑平均灰度、皮层灰度、皮层下灰度和海马灰度 ,与非缺血侧相应部位及对照组相应部位比较有显著差异 (P<0 .0 0 1) ,对照组脑片左右侧及对照组与缺血组非缺血侧比较无显著差异 (P>0 .0 5 )。结论 :透光法可用于局灶性脑缺血的定量分析。

Objective: To evaluate the feasibility of light transmission to measure focal cerebral ischemia in mice. Methods: Persistent focal cerebral ischemia was induced by middle cerebral artery occlusion (MCAO) in mice. The brains were removed 24 h after MCAO and coronally dissected into 1 mm sections. Using a stereomicroscope, the brain section was illuminated with a halogen lamp and computerized images were stored. Next the brain sections were stained for 30 minutes with 0.5%TTC (2,3,5 triphenylterzolim chloride ) at 37℃. Using an image analyzer (AnalyPower1.0), the infarct volumes obtained by light transmittance and TTC staining were calculated. Integrated gray scales of sections of both hemispheres were calculated by Photoshop 5.0. Results: A close correlation existed between cerebral infarct volume measured by light transmission and TTC staining ( r =0.81). The mean gray scales measured by both techniques of the ischemic hemispheres as well as those of the cortex, subcortex and hippocampus were significantly higher than those of non ischemic hemispheres and of control mouse hemispheres ( P <0.001). Further there were no significant difference between the two hemispheres of control mice and bet ween hemispheres of control mice and non ischemic hemispheres of the MCAO mice. Conclusion: Light transmission can be used for qualitative analysis of focal cerebral ischemia.