人参皂苷Rg2对脑缺血再灌注大鼠学习记忆及海马神经元Glu和NMDA受体亚单位表达的影响

目的观察全脑缺血再灌注对大鼠空间学习记忆和海马神经元Glu、N-甲基-D-天冬氨酸受体(NMDAR)亚单位NR1、NR2B表达的影响,探讨人参皂苷Rg2的干预作用。方法SD大鼠56只,采用四血管阻断法制备大鼠全脑缺血再灌注模型(假手术组除外),随机分为7组(各8只):假手术组、模型组、溶酶组(注射2.5 mL/kg的1,2-丙二醇和聚乙二醇400混合液)、人参皂苷Rg2高剂量组(注射10.0 mg/kg人参皂苷Rg2)、中剂量组(注射5.0 mg/kg人参皂苷Rg2)、低剂量组(注射2.5 mg/kg人参皂苷Rg2)、尼莫地平组(注射50μg/kg尼莫地平),MORRIS水迷宫试验检测大鼠学习记忆能力的改变,免疫组织化学和图像分析方法观察Glu、NR1、NR2免疫阳性神经元的表达。结果缺血再灌注模型组大鼠海马Glu、NR1、NR2B免疫阳性神经元的表达与假手术组比较明显增加,人参皂苷Rg2高剂量组Glu、NR1、NR2B神经元的表达与模型组比较明显降低,差异均有显著意义(F=155.249~268.228,q=2.934~5.259,P<0.01)。人参皂苷Rg2高剂量组大鼠逃避潜伏期较模型组明显缩短(F=22.063,q=4.59,P<0.01)。结论人参皂苷Rg2能降低Glu、NR1、NR2B在脑缺血再灌注损伤大鼠海马神经元的表达,并改善学习记忆能力。

EFFECTS OF GINSENOSIDE Rg2 ON LEARNING AND MEMORY AND EXPRESSION OF GLU, NR1 AND NR2B OF HIPPOCAMPUS NEURONS IN RATS WITH BRAIN ISCHEMICAL REPERFUSION

ObjectiveTo observe the effects of ginsenoside Rg_2 on the space learning and memory and the expression of Glu,NMDA receptor subunits NR_1 and NR_(2B) of hippocampus neuron in rats with whole brain ischemic reperfusion.Methods(Four-vessel occlusion) was performed on rats(n=56) to produce a whole brain ischemic reperfusion model.Ginsenoside Rg_2 in high(10.0 mg/kg BW),moderate(5.0 mg/kg BW) and low dosages(2.5 mg/kg BW) were given respectively to the rats in experimental groups(n=8 in each group).MORRIS Water Maze method was used to detect the ability of learning and memory,immunohistochemistry and image analysis performed to study the expressions of Glu,NR_1 and NR_(2B) of the hippocampus neuron from different groups.ResultsThe expressions of Glu,NR_1 and NR_(2B) of hippocampus neurons of the model rats were more obvious than that of sham-operation rats,while such expressions were significantly reduced after the model animals received a high dose of ginsenoside Rg_2(F=155.249-268.228,q=2.934-5.259,P<0.01).The escaping eclipse period of the experimental rats receiving a high dose of ginsenoside Rg_2 was significantly shorter than that of the model rats(F=22.063,q=4.59,P<0.01).ConclusionGinsenoside Rg_2 can decrease the expressions of Glu, NR_1 and NR_(2B) of hippocampus neurons of rats with ischemic reperfusion injury,and improve their ability of learning and memory.