脑内同步灌流NaN_3致大鼠mPFC和海马细胞外液中胆碱类递质含量变化

Effect of synchronous perfusion of NaN_3 in changes in content of cholinergic neurotransmitter in medial prefrontal cortex and hippocampal extra-cellular fluid

目的:观察脑内同步灌流特异性呼吸链复合体Ⅳ抑制剂叠氮钠(sodium azide,NaN3)对大鼠腹内侧前额叶皮质(mPFC)和海马细胞外液中乙酰胆碱(ACh)和胆碱(Ch)含量的影响,建立线粒体损伤的AD急性模型。方法:应用脑双位点双通道同步微透析采样技术,对清醒自由活动正常大鼠mPFC和海马同步灌流含NaN3(50μmol·L-1)和新斯的明(2μmol·L-1)的改良Ringer氏液120 min,并同步连续收集两脑区的透析液。采用高效液相色谱-柱后固定化酶反应器-电化学法动态监测ACh和Ch含量。结果:正常大鼠的mPFC细胞外液中ACh和Ch含量高于海马区,NaN3在灌流期间能明显降低mPFC/海马细胞外液中ACh,但显著升高Ch,并持续抑制mPFC/海马区ACh和Ch含量恢复。结论:大鼠脑内mPFC和海马同步灌流NaN3使胆碱能神经投射区域功能受损,可造成ACh和Ch代谢紊乱的AD急性模型,可用于病理机制和药理学研究。

Objective： To observe the effect of synchronous perfusion of specific respiratory chain complex IV inhibitor sodium azide （ NaN3 ） in brain on rat ventromedial prefrontal cortex （mPFC） and acetylcholine （ACh） and choline （Ch） contents in hippocampal extra-cellular fluid, and establish the AD rat model induced by mitoehondrial acute injury. Method： The synchronous dualprobe dual-channel brain microdialysis sampling technology was applied to synchronously perfuse modified Ringer＇s solution containing NaN3 （50 umol . L-1） and neostigmine （2 umol . L-1） into mPFC and hippocampus of conscious, freely moving normal rats, and continuously collect dialysates from different encephalic areas. Dynamic contents of ACh and Ch were determined by high performance liquid chromatography-post-column immobilized enzyme reactor-electrochemical process. Result： ACh and Ch contents in mPFC extracellular fluid of normal rats were higher than that in hippocampus. During the process of perfusion, NaN3 could significantly reduce ACh in mPFC/hippocampal extra-cellular fluid, but remarkably increase Ch, and constantly inhibit the recovery of ACh and Ch contents in mPFC/hippocampus. Conclusion ： The synchronous perfusion of NaN3 in rat mPFC and hippocampus can injure functions of the cholinergic nerve projection area, and cause the acute AD model with ACh and Ch metabolic disorders. This model can be used in pathogenetic and pharmacological studies.