电针对吗啡戒断大鼠杏仁核内N-甲基-D-天门冬氨酸受体亚单位NR2B蛋白及基因表达的影响

目的:观察电针对吗啡戒断大鼠空间学习记忆的影响,通过对杏仁核脑区N-甲基-D-天门冬氨酸受体亚单位NR 2B表达的检测,探讨电针改善大鼠吗啡戒断后学习记忆能力的分子生物学机制。方法:雄性SD大鼠,随机分为空白组、模型组、针刺组以及电针组,每组10只。以每日20,30,40,50,50mg/kg剂量,连续5d背部皮下注射盐酸吗啡,建立吗啡依赖大鼠模型,末次注射后3h给予纳洛酮快速戒断。两个治疗组选取"足三里""肾俞"穴分别施以手针和电针,每次15min,每日1次,连续治疗6d。应用Morris水迷宫测试戒断大鼠空间学习能力,应用蛋白印记(Western blot)及实时荧光定量聚合酶链反应(RT-PCR)技术检测戒断大鼠杏仁核NR 2B蛋白与基因的表达水平。结果:模型组大鼠的逃避潜伏期较空白组明显延长(P0.01),针刺及电针组则较模型组显著缩短(P0.01),电针组较针刺组缩短更明显(P0.05);模型组大鼠的杏仁核NR 2B蛋白表达较空白组显著降低(P0.01),针刺组、电针组则较模型组表达升高(P0.01),电针组高于针刺组(P0.01);模型组NR 2BmRNA表达较空白组显著降低(P0.01),电针组较模型组表达升高(P0.05)。结论:吗啡戒断后大鼠空间学习能力受损,针刺及电针可以恢复大鼠学习能力且电针组疗效优于针刺组,推测可能与其对杏仁核NR 2B表达的调节有关。

Effect of Electroacupuncture Intervention on Expression of NR 2 B Subunit of NMDA Receptor in Amygdala during Morphine Withdrawal in Rats

Objective To observe the effect of electroacupuncture(EA)on the spatial learning-memory ability and the expression of NR 2Bsubunit of NMDA receptor in the amygdala(AMG)in rats with morphine withdrawal.Methods A total of40 SD rats were randomized into control,model,manual acupuncture and EA groups(n=10in each group).The morphine withdrawal model was established by subcutaneous injection of morphine hydrochloride injection at doses of 20,30,40,50and50mg·kg-1·d-1 continuously for 5days,followed by injection of naloxone(i.p.,3mg/kg)for rapid induction of withdrawal syndrome.Manual acupuncture or EA stimulation was applied to bilateral"Shenshu"(BL 23)and "Zusanli"(ST 36),once daily for 6days.Morris water maze swimming test was conducted for detecting the rats' spatial learning-memory ability.The expression levels of NR 2Bprotein and mRNA in AMG was measured by Western blot and Real time-PCR,respectively.ResultsCompared to the control group,the escape latency on day 5of swimming tests was obviously prolonged in the model group(P<0.01),while in comparison with the model group,the escape latencies in both manual acupuncture and EA groups were obviously shortened(P<0.01),suggesting an improvement of the rats' learning-memory ability.In addition,the expression levels of NR 2Bprotein in both manual acupuncture and EA groups and that of NR 2BmRNA in the EA group were significantly higher than those of the model group(P<0.01,P<0.05).Conclusion Both manual acupuncture and EA interventions can improve the learning-memory ability in morphine withdrawal rats,which is probably partially related to their effects in up-regulating the expression of NR 2Bin the AMG.