黄芩茎叶总黄酮预处理对脑缺血再灌注皮质神经元热休克蛋白70及超微结构的保护作用

Protective effect of scutellaria baicalensis stem-leaf total flavonoid on expression of heat shock protein 70 and ultrastructure in cortex neurons following cerebral ischemia reperfusion

目的：探讨黄芩茎叶总黄酮（SSTF）预处理对大鼠脑缺血再灌注（IR）皮质神经元热休克蛋白70（HSP70）的表达及超微结构的保护作用.方法：线栓法制备脑缺血再灌注模型;免疫组织化学法和透射电镜观察皮质神经元HSP70的表达和超微结构改变.结果：假手术组HSP70仅有微量表达,超微结构正常;模型组HSP70阳性面积率增加,神经元多见坏死,部分胞膜崩解,核膜不完整,染色质呈块状凝集,线粒体肿胀,外膜或嵴断裂,内质网扩张;SSTF预处理组较模型组HSP70阳性面积率增加,多数神经元较正常,核模较完整,染色质均匀,线粒体损伤减轻,内质网趋于正常,凋亡细胞少见.结论：SSTF预处理可上调皮质神经元HSP70的表达,改善超微结构损伤,对脑IR损伤有一定的预防性保护作用.

Objective： To investigate the effect of scutellaria baicalensis stem-leaf total flavonoid （SSTF） on the expression of heat shock protein 70 （HSP70） and ultrastructure in the cortex neuron induced by focal cerebral ischemia reperfusion （IR） in rats. Methods： The model of focal cerebral isehemia reperfusion was built up on rats using the suture embolizatioru The ex pression of HSP70 and ultrastructure of the cerebral cortex were observed by immunohistochemical techniques and electron microscopy. Results： A few positive cells were expressed （0. 017±0. 011） and its ultrastructure looked normal in the sham operated group; in the model group, the positive area rate of HSP70 increased （0. 038 ± 0. 010）, many necrosis were obeserved, part of the membrane was dissolved, mitochondria was swelling with endoplasmic reticulum dilatation, nuclear membrane was incomplete, and chromatin showed massive agglutination. Compared to the model group, the positive area rate of HSP70 increased sharply （0. 069±0. 010）, the shape of cells was relatively regular, apoptosis was rare, mitochondria swelling decreased, endoplasmic retieulum and nuclear membrane tended to normal and complete, and chromatin rela- tively showed neurons in the SSTF interferred group. Conclusion： SSTF can protect the cerebral cortex from IR injury by upregulating the expression of HSP70 and improving the ultrastructure of the neurons.