吗啡戒断大鼠脊髓和脑干以及前脑皮层胶质细胞源性神经营养因子及受体mRNA的表达

The expression of glial cell derived neurotrophic factor and its receptor GDNFR α and GDNFR β mRNA in spinal cord, brainstem and frontal cortex during morphine withdrawal in rats

目的 观察吗啡依赖或戒断时大鼠脊髓、脑干和皮层胶质细胞源性神经营养因子 (glialcellderivedneurotrophicfactor,GDNF)以及受体GDNFR α和GDNFR β基因的表达以及毒蕈碱乙酰胆碱受体 (mAch)、N 甲基 D 天门冬氨酸 (NMDA)受体拮抗剂或一氧化氮合酶 (NOS)抑制剂处理后对它们表达的影响 ,并观察侧脑室注射GDNF反义寡核苷酸对吗啡戒断症状的影响。方法 利用逆转录聚合酶链反应 (RT PCR) ,以 β actinmRNA作为内标检测GDNF、GDNFR α和GDNFR βmRNA ,应用lipofectAMINE转染GDNF反义寡核苷酸 ,戒断症状评分根据纳洛酮注射后 1h内的各项症状的分值。结果 吗啡依赖时脊髓和脑干中GDNF基因表达增加 ,GDNFR α和GDNFR β基因的表达轻微增加 ,吗啡依赖大鼠注射纳洛酮 1h后脊髓和脑干GDNF、GDNFR α和GDNFR β基因表达较依赖组降低 ,2h后增加 ,4h后接近正常。大鼠前脑皮层GDNF和GDNFR α基因的基因表达水平较低 ,当注射纳洛酮 1、2和 4h后前脑皮层GDNF、GDNFR α和GDNFR β基因的表达明显增加。在注射纳洛酮前 30min给予NOS抑制剂L N 硝基精氨酸甲酯 (1 0mg/kg) ,脊髓中GDNF和GDNFR β基因以及前脑皮层中GDNFR α和GDNFR β基因的表达较戒断组减少 ;给予MK80 1 (0 1 2 5mg/kg)后前脑皮层GDNF和GDNFR ?

Objective To investigate the expression of glial cell derived neurotrophic factor (GDNF) and its receptor GDNFR α(GFRα 1) and GDNFR β(Ret) genes and the effects of muscarinic receptor antagonists, NMDA receptor antagonist, inhibitor of nitric oxide synthase on the expression of these genes in the spinal cord, brainstem and frontal cortex during morphine withdrawal, and to observe the effects of GDNF antisense oligoneucleotide (i c v) on the morphine withdrawal symptoms in rats Methods The levels of GDNF, GDNFR α and GDNFR β mRNA were assayed by reverse transcription polymerase chain reaction (RT PCR) with the β actin mRNA as an internal control Results The GDNF mRNA levels were increased, and GDNFR α and GDNFR β mRNA levels was slightly increased in the spinal cord and brainstem during morphine dependence These genes were decreased at 1 h, increased at 2 h after administration of naloxone in morphine dependent rats While the GDNF , GDNFR α and GDNFR β levels in the frontal cortex were increased significantly at 1, 2 and 4 h after the injection of naloxone during morphine withdrawal The pre treatment with L N nitric arginine methylester (10 mg/kg), the expressions of GDNF and GDNFR β in the spinal cord, both GDNFR α and GDNFR β in the frontal cortex were decreased The expressions of both GDNF and GDNFR α in the frontal cortex were decreased by treatment with MK801 (0 5 mg/kg), and the expressions of GDNF in both the stem and cortex, and GDNFR β in the brainstem decreased by treatment with the methyl scopolamine (0 5 mg/kg) The β actin mRNA levels were not different in each group Moreover, the morphine withdrawal symptoms were attenuated by intracerebroven tricular injection of GDNF antisense oligoneucleotide in 6 hour and 24 hour before naloxone administration in morphine dependent rats Conclusion The results not only provide direct evidence that the expressions of GDNF and its receptors mRNA in glial cells play an important role in mediating the process of morphine dependence and may be account for the long term neuro adaptation associated with morphine dependence, but also suggest that muscarinic receptor, NMDA receptor and nitric oxide pathways may be involved in the expression of GDNF and GDNF receptor genes during morphine withdrawal