胡黄连苷Ⅱ对脑缺血损伤后神经细胞凋亡和超微结构的影响

Effect of picroside Ⅱ on neuronal apoptosis and ultrastructure in cerebral ischemic injury in rats

目的探讨胡黄连苷Ⅱ对脑缺血损伤后神经细胞凋亡和超微结构的影响。方法成年健康♂Wistar大鼠60只,应用线栓法建立大鼠脑缺血模型,经腹腔注射胡黄连苷Ⅱ(20 mg·kg-1)干预治疗,改良神经功能评分(m NSS)评价动物神经行为功能,氯化三苯基四氮唑染色观察脑梗死体积,HE染色和透射电镜观察脑组织病理和超微结构,原位末端标记法检测细胞凋亡,免疫组织化学和Western blot检测p-ERK1/2表达水平。结果大鼠脑缺血损伤后表现出神经功能障碍和脑梗死病灶,皮质区神经元和血脑屏障结构损伤较重,皮质区凋亡细胞数量和p-ERK1/2蛋白表达较对照组明显增多(P<0.05)。治疗组大鼠mN SS评分和脑梗死体积较模型组明显降低(P<0.05),皮质区神经元和血脑屏障损伤减轻,凋亡细胞与p-ERK1/2表达水平较模型组明显降低(P<0.05)。结论胡黄连苷Ⅱ可能抑制神经细胞凋亡,改善缺血区脑组织的形态结构,促进大鼠神经行为功能恢复。

Aim To explore the effect of picroside II on neuronal apoptosis and ultrastructure after cerebral ischemic injury in rats. Methods The focal cerebral ischemic models were established by inserting a mono-filament thread into middle cerebral artery occlusion （ MCAO） in 60 Wistar rats and treated by injecting picroside Ⅱ （ 20 mg · kg-1 ） intraperitoneally. The neurobehavioral function was evaluated by modified neurological severity score test. The cerebral infarct volume was measured by tetrazolium chloride staining. The morphology and ultrastructure of brain tissue were observed by hematoxylin-eosin staining and transmis-sion electron microscopy respectively. The apoptotic cells were counted by terminal deoxynucleotidyl trans-ferase dUTP nick end labeling assay and the expression of p-ERK1/2 was determined by immunohistochemical assay and Western blot. Results The neurological be- havioral malfunction and the cerebral infarct appeared in rats with MCAO. In model group, the damage of neurons and blood brain barrier （BBB） in cortex wors- ened, while the number of apoptotic cells and the ex- pression of p-ERK1/2 increased more significantly than those in control group （ P 〈 0. 05 ）. In treatment group, the neurological behavioral function, morpholo- gy, ultrastructure of neuron and BBB were improved, the cerebral infarct volume, the number of apoptotic ceils and the expression of p-ERK1/2 decreased more significantly than those in model group （ P 〈 0. 05 ）. Conclusion Picroside II might reduce cell apoptosis to improve the morphology and ultrastructure of cere- bral ischemic tissue and recover the neurobehavioral function of rats.