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[摘要]
目的 探讨三七总皂苷(TSPN)对全脑缺血大鼠学习记忆的影响及其作用机制。方法 采用四血管阻断法制作全脑缺血模型。大鼠分成假手术组、模型组和TSPN组。TSPN组大鼠全脑缺血后30 min ip给予剂量为75 mg/kg的TSPN,1次/d,模型组给予等体积生理盐水,1次/d,连续14 d。再灌注14 d后采用Morris水迷宫检测大鼠的学习记忆能力,免疫组织化学观察海马CA1区NeuN(成熟神经元),齿状回颗粒细胞下层(SGZ)DCX(微管蛋白)的表达,免疫印迹技术检测海马CA1区DCX蛋白的表达。结果 与模型组相比,TSPN组逃避潜伏期显著缩短(P<0.05),跨越平台次数增加(P<0.05);TSPN组海马CA1区NeuN+细胞密度显著高于模型组(P<0.01);TSPN组SGZ区DCX+细胞和蛋白水平均显著多于模型组(P<0.01)。结论 TSPN可以改善全脑缺血后大鼠的学习记忆能力,其机制与促进海马神经再生有关。
[Key word]
[Abstract]
Objective To explore the effect of the total saponins of Panax notoginseng (TSPN) on learning and memory of global cerebral ischemia rats and its mechanism. Methods Using four-vessel occlusion method to establish the global cerebral ischemia model. Rats were divided into sham group, vehicle group, and TSPN group. The rats in the TSPN group were administered TSPN intraperitoneally 30 min post-brain ischemia. The dose of TSPN (75 mg/kg) was suspended in 0.9% saline 10 g/L, once per day for 14 d after reperfusion. Rats in the vehicle group were treated with equal volume of 0.9% saline, one injection per day for 14 d. The Morris Water Maze was performed to test the learning and memory of rats and doublecortin (DCX) and NeuN expression in the hippocampus was assessed by immunohistochemistry. Furthermore, immunoblotting was adopted to test the protein level of DCX in the CA1 subfield of hippocampus. Results The escape latency in the vehicle group was longer than that in the TSPN group (P<0.05). The times across the platform were less in the vehicle group than that in the TSPN group (P<0.05). In comparison with the vehicle group, the number of the NeuN+ cells in the CA1 subfield and DCX+ cells in the SGZ of the TSPN group were significantly increased (P<0.01); Moreover, the result of immunoblotting demonstrated that the protein level of DCX in the CA1 subfield of hippocampus of the TSPN group was significantly higher than that in the vehicle group (P<0.01). Conclusion TSPN could improve the learning and memory of global cerebral ischemia rats and its mechanism may be related to the promotion of hippocampus neurogenesis.
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[基金项目]
益阳市科技局应用基础研究项目(2017YR02);湖南省自然科学基金青年课题(2018JJ3517);湖南省中医药管理局科研项目(201932);湖南省教育厅优秀青年课题(16B269)