【作者】 李晓春；

【导师】 邹莉波；

【作者基本信息】 沈阳药科大学 ， 药理学， 2009， 硕士

【摘要】 本论文主要研究了文冠果壳苷对反复脑缺血再灌注小鼠学习记忆障碍的改善作用,并初步探讨了其作用机制。通过Y迷宫、新物体辨别、水迷宫、跳台等行为学实验方法考察了文冠果壳苷对小鼠反复脑缺血再灌注所致学习记忆障碍的影响；用生化学方法检测小鼠皮层中Ca2+-Mg2+-ATPase、总ATPase以及总NOS的活力；用免疫组织化学的方法,考察了文冠果壳苷对小鼠海马组织CA1区NMDA受体-2B蛋白表达的影响；用HE染色的方法,观察了小鼠海马组织结构的改变。实验结果表明,反复脑缺血再灌注明显影响了小鼠空间学习记忆能力、物体辨别能力,而文冠果壳苷0.32、0.02 mg/kg剂量组能够显著提高小鼠自发交替反应正确率；提高新物体辨别实验中的辨别系数和优先指数；剂量依赖性地缩短水迷宫实验中小鼠到达安全台的游泳时间。同时文冠果壳苷0.32、0.02 mg/kg剂量组能够不同程度地提高反复脑缺血再灌注所致痴呆小鼠皮层中Ca2+-Mg2+-ATPase、总ATPase的活性,降低NOS的活性,提高小鼠海马组织NMDA受体-2B蛋白表达水平。小鼠海马组织HE染色结果显示,文冠果壳苷能够减轻反复脑缺血再灌注所致的神经细胞肿胀变性、核固缩、核仁、轴突不清,局部神经元缺失等病理改变。综上所述,文冠果壳苷对反复脑缺血再灌注小鼠学习记忆障碍具有显著的改善作用,其作用机制可能与改善脑细胞能量代谢、维持离子稳态、对抗谷氨酸毒性以及降低NO含量有关。更多还原

【Abstract】 In this paper, we studied the effect of Xanthoceraside on learning and memory impairment in mice induced by cerebral ischemia-reperfusion. The Y-maze test, novel object recognition test, water maze test and step-down test were performed to investigate the effect of Xanthoceraside on learning and memory impairment in mice by cerebral ischemia-reperfusion. The activity of Ca2+-Mg2+-ATPase, total ATPase and total NOS were measured by biochemical methods.The paraffin slices of hipocampus were made and NMDA receptor was dyed throughimmunohistochemistry. The morphology of cerebral hippocampus was determined by HE staining. The results showed that the administration of Xanthoceraside (0.32,0.02mg/kg) increased the percentage alternation in Y maze test, the exploration and preferential index in novel object recognition test, reduced the latency to find the terminal platform in water maze test and the number of error and prolonged the latency in step-down test compared with the model mice impaired by cerebral ischemia-reperfusion. The decrease of activities of Ca2+-Mg2+-ATPase, total ATPase and the increase of NOS in mice impaired by cerebral ischemia-reperfusion were significantly prevented by administration of Xanthoceraside. Moreover, the results of immunohistochemistry showed that Xanthoceraside could increase the content of NMDA receptor-2B significantly. It also showed that Xanthoceraside prevented the nerve cell in the cerebral hippocampus from the damages of cerebral ischemia-reperfusion on the basis of pathology.These findings indicate that Xanthoceraside has the effect of improving learning and memory impairment in mice induced by cerebral ischemia-reperfusion. The mechanism may be associated with the improvement of metabolisn of brain and the modulation of calcium homeostasis; the antagonism against glutamate and the inhibition of NO.更多还原