补肾方药对衰老大鼠海马学习记忆相关基因BDNF及其受体TrkB mRNA表达的影响

目的:观察补肾方药左归丸、右归丸对衰老大鼠海马学习记忆相关基因脑源性神经营养因子(BDNF)及其受体TrkB mRNA表达的影响,探讨老年大鼠学习记忆功能减退的部分分子机理,以及左归丸、右归丸的改善作用。方法:以自然衰老SD大鼠为动物模型,随机分设4组:青年对照组、老年对照组、老年左归丸组、老年右归丸组。采用原位杂交技术,观察各组大鼠大脑切片海马各分区(CA1、CA2、CA3、DG)BDNF、TrkB mRNA表达变化。结果:与青年对照组相比,老年对照组大鼠海马各分区的BDNF、TrkB mRNA表达均明显减弱(P<0.05),而左归丸、右归丸能不同程度地提高老年对照组大鼠海马DG、CA1、CA2、和CA3分区低下的BDNF、TrkB mRNA的表达。结论:老年大鼠的学习记忆功能退化,与学习记忆相关的基因BDNF、Trk B表达异常有关。而滋补肾阴方药左归丸、温补肾阳方药有归丸能通过提高BDNF、TrkB基因的表达,进而改善老年大鼠的学习记忆功能,延缓机体衰老。

Effects of kidney-nourishing herbs on cognition-related gene BDNF and its receptor TrkB mRNA expressions in aging rats' hippocampus

Objective:To observe the effects of Zuogu Pill and Yougui Pill on mRNA expressions of BDNF(brain derived neurotrophic factor),a cognition related gene,and its receptor TrkB in the hippocampus of aging rats,to discuss some molecular mechanisms on cognition deterioration of old rats.Methods:To take naturally ageing rats as animal model and divided them into four groups randomly:young control group,senile control group,senile Zuogui Pill group and senile Yougui Pill group. In situ hybridization is used to determine the BDNF and TrkB mRNA expressions in hippocampal subregions(CA1,CA2,CA3, DG)of rats in each group.Results:Compared with young control group,BDNF and TrkB mRNA expressions in senile control group diminished obviously(P<0.05).The results showed that Zuogui Pill and Yougui Pill can improve the learning and memory and delay aging by raising the expressions of BDNF and TrkB in CA1,CA2,CA3,DG in different degrees.Conclusion:Cognition deterioration of old rats is related to the abnormality of BDNF and Trk B mRNA expressions.Zuogui Pill and Yougui Pill can improve the cognition ability and slow down aging process through improving BDNF,TrkB expressions.