创伤性脑损伤后大鼠脑线粒体功能的变化

Changes of mitochondrial function in rat brain after traumatic brain injury

目的通过改进型Feeney自由落体脑损伤装置制作大鼠重型颅脑损伤模型,检测损伤后不同时间点脑皮质组织线粒体功能的变化。方法雄性SD大鼠30只,按随机数字表法分为假手术组(n=5)和创伤性脑损伤(TBI)组(n=25),TBI组按伤后不同时间点(12 h、1 d、3 d、5 d、7 d)又分为5个亚组,每组分别5只动物。采用尼氏染色观察神经细胞损伤;采用多功能酶标仪检测线粒体膜电位(MMP)、H^+-ATPase活性、三磷酸腺苷(ATP)含量,观察TBI后脑皮质线粒体功能的变化。结果 TBI后尼氏染色结果显示,脑皮质神经元染色12 h组较假手术组神经元减少,1 d组更少,3 d组染色最少。MMP、H^+-ATPase活性、ATP含量在伤后均下降,且3 d组最低,相较于假手术组有显著性差异(P<0.05)。结论 TBI后脑皮质线粒体功能呈现先下降、后上升的趋势,尚可恢复部分功能,这对TBI后脑保护的机制研究提供了一定的实验基础,对脑损伤者进行有效的保护至关重要。

Objective To set up severe rats traumatic brain injury （TBI） model through modified Feeney free fall brain injury device and investigate the pathogenesis on brain cortical tissue mitochondrial function changes in different time. Methods Thirty adult male Sprague-Dawley （SD） rats were used in the study and randomly divided into 2 groups, sham operation group （n=5） and TBI group （n=25）. TBI group was divided into five subgroups at different time points after injury （12 h, 1 d, 3 d, 5 d, 7 d） and five rats in each subgroup. The damage of neuron was observed by Nepal＇s staining. Mitochondrial membrane potential （MMP）, H ＋-ATPase activity and adenosine triphosphate （ATP） content were tested by multifunctional enzyme-labeled instrument to observe the changes of cerebral cortex mitochondria after TBI. Results The post-TBI Nissl staining showed that compared with the sham group, the cortical neurons reduced in staining 12 h group, 1 d group more less, and 3 d group was the least. The MMP, activity of H＋-ATPase and the content of ATP all decreased after injury, and 3 d group was the least, which had a significant difference compared to the sham operation group （P〈0.05）. Conclusions The post-TBI mitochondrial function in cerebral cortex first decreased and then increased, which can restore some function. This has provide a certain experimental basis on the research of post-TBI brain protection mechanism, and showed an importance to effective protection on brain injury patients.