葛根素对缺氧缺血脑损伤后学习记忆能力及NMDA受体的影响

Effects of puerarin on learning and memory and NMDAR in rats following hypoxic-ischemic brain damage

目的:观察葛根素(Puerarin,Pue)对新生鼠缺氧缺血后学习记忆的远期影响及其可能机制。方法:7 d龄SD大鼠随机分为3组:假手术组(Sham组);对照组(Con组);葛根素组(Pue组)。各组分别于8周龄时Morris水迷宫检测其学习记忆能力,于3、4周和8周龄时采用免疫组化方法检测各组NR2A和NR2B在海马CA1区的表达。结果:①8周时Con组比Sham组平均潜伏期明显延长(P<0.05),穿越平台次数显著减少(P<0.01);与Con组相比,Pue组的平均潜伏期和穿越平台次数均得到明显改善(P<0.05)。②Con组3、4周和8周时海马CA1区NR2A和NR2B的表达均明显低于Sham组(P<0.01);Pue组NR2A蛋白在3周和8周时的表达比同一时间点Con组明显增多(P<0.05),NR2B蛋白在3周和4周时的表达明显比Con组增多(P<0.05)。结论:Pue能提高缺氧缺血新生大鼠年长后的学习记忆能力,其保护作用可能和Pue增加海马CA1区NR2A和NR2B的表达有关。

Objective：To investigate the effects of puerarin on learning and memory ability after hypoxia-ischemia brain damage and to understand the underlying mechanisms.Methods：A total of 102 S-D rats（P7）were randomly assigned to three groups（n=34）：sham group,Con group,and puerarin group.At 8 weeks after birth,learning and memory ability were tested by Morris water maze.At 3,4,8 weeks after birth,expressions of NR2A and NR2B were detected in the CA1 region of the hippocampus by immunohistochemistry.Results：①The average time of escape latency was significantly longer and the number of platform location crossing was less in Con group than these in sham group（P〈0.05,P〈0.01）.Compared with Con group,the average time of escape latency was significantly shorter（P〈0.05）and the number of platform location crossing was more（P〈0.05）in puerarin group.②The expression levels of NR2A and NR2B in hippocampal CA1 areas in the Con group were less than those in the sham-operated rats at any time points（P〈0.01）.These levels of NR2A were significantly increased in the puerarin group when the rats were 3 w and 8 w of age,compared with the Con group（P〈0.05）.These levels of NR2B were significantly increased in the puerarin group when the rats were 3 w and 4 w of age,compared with the Con group（P〈0.05）.Conclusion：Puerarin can improve learning and memory in hypoxia-ischemia brain damage rats.This protection may be associated with the increased NR2A and NR2B in the CA1 region of hippocampus.