M受体对吗啡戒断大鼠脊髓和脑干NMDA受体基因表达及中脑导水管周围灰质中谷氨酸释放的调节  

Muscarinic receptors modulate the mRNA expression of NMDA receptors in brainstem and the release of glutamate in periaqueductal grey during morphine withdrawal in rats

作　　者：刘惠芬[1] 周文华[1] 谢小虎[1] 曹君利[1] 顾钧[1] 杨国栋[1] 

机构地区：[1]宁波市微循环与莨菪类药研究所,宁波戒毒研究中心宁波315010

出　　处：《生理学报》2004年第1期95-100,共6页Acta Physiologica Sinica

基　　金：This work was supported by the National Natural Science Foundation of China(No.30100051).

摘　　要：应用鞘内注射反义寡脱氧核苷酸技术和RT-PCR反应,观察毒蕈碱型乙酰胆碱受体(muscarinic acetylcholine receptor,M)对吗啡依赖大鼠脊髓和脑干NMDA受体NR1A和NR2A mRNA表达和中脑导水管周围灰质区(periaqueductal grey,PAG)中谷氨酸释放的影响。结果显示,吗啡依赖大鼠脊髓NR1A和NR2AmRNA表达明显升高,而脑干中NR1A和NR2AmRNA表达没有显著变化;注射纳洛酮后1 h,吗啡戒断大鼠脊髓和脑干中NR1A和NR2A表达显著高于依赖组,经NMDA受体拈抗剂MK801(0.125 mg/kg,i.p.)、M受体拮抗剂东莨菪碱(0.5 mg/kg,i.p.)、M.受体拮抗剂呱伦西平(10 mg/kg,i.p.)和NOS抑制剂L-NAME(10 mg/kg,i.p.)处理后,脊髓和脑干中NR1A和NR2A基因表达都较戒断组明显减少。在纳洛酮激发前24 h鞘内注射NR1A和M2受体的反义寡脱氧核苷酸(4 μg/只),戒断症状评分值及脊髓和脑干的NR1AmRNA的表达均较对照组明显减少。吗啡依赖大鼠在纳洛酮注射前24 h鞘内注射M2受体反义寡脱氧核苷酸(4μg/只),可以明显减少PAG内透析液中谷氨酸含量。上述结果提示:NMDA受体的基因表达和谷氨酸释放参与吗啡成断过程,而这种表达受到M受体的调节。The antisense approach and RT-PCR were used to study the effects of muscarinic receptors on the scores of morphine-withdrawal syndrome and the expression of NMDA receptor subtypes (NR1A and NR2A) mRNA in rat spinal cord and brainstem. The concentrations of glutamate in periaqueductal grey (PAG) of morphine-withdrawal rats were determined by capillary electrophoresis with laser-induced fluorescence detection. The data showed that the NR1A and NR2A mRNA levels were increased significantly in the spinal cord and brainstem 1 h after the injection of naloxone (4 mg/kg, i.p.) in morphine-dependent rats. Moreover, in morphine-dependent rats pretreated (i.p.) with scopolamine (0.5 mg/kg), or pirenzepine (10 mg/kg), MK801 (0.125 mg/kg), L-N-nitroarginine methylester (10 mg/kg) 30 min before naloxone injection, the NR1Aand NR2A mRNA levels were significantly lower than those of 1 h morphine-withdrawal rats. Intrathecal injection of NR1A or M2 receptor antisense oligonucle-otides (A-oligo, 4 μg/per rat) 24 h prior to naloxone challenge could block the morphine withdrawal symptoms including wet dog shaking, irritability, salivation, diarrhea, chewing and weight loss. Meanwhile, in morphine-dependent rats the NR1A mRNA levels in the spinal cord and brainstem were down-regulated by intrathecal injection of M2 receptor A-oligo. The glutamate concentra- tions in PAG microdialysis were increased to a maximal level 15 min after naloxone injection. The glutamate response was inhibited by pretreatment with M, receptor A-oligo but not by M1 A-oligo. The results suggest that the expression of NMDA receptors and the release of glutmate in brainstem are involved in the processes of morphine withdrawal and that the NMDA receptor expression is possibly regulated by the muscarinic receptors during morphine withdrawal.

关 键 词：吗啡依赖 戒断反应 NMDA受体 毒蕈碱乙酰胆碱受体 一氧化氮合酶 

分 类 号：Q426[生物学—神经生物学]