甲基苯丙胺急性暴露对小鼠神经元的损伤作用研究

目的 探讨甲基苯丙胺(METH)急性暴露后引起神经元的损伤作用.方法 甲基苯丙胺给与小鼠后,对小鼠的刻板行为进行评分,通过Y水迷宫的方法评估小鼠空间记忆能力.分子水平,试剂盒法检测皮层区诱导型NO释放水平,利用Western-blot法观察神经元凋亡标志性蛋白Bax、Bcl2及Caspase 3表达水平.在细胞水平,利用彗星实验,观察甲基苯丙胺对原代培养神经元DNA的损伤情况.利用JC-1探针观察甲基苯丙胺对神经元线粒体膜电位的改变.此外,通过Western-blot法,阐述MAPKs通路在METH引起神经元损伤中的潜在作用.结果 METH显著增加小鼠的刻板行为,且明显降低小鼠空间识别能力.在分子层面,发现诱导型NO含量显著增高,相应凋亡蛋白Bax和cleaved caspase-3的表达增高,神经元细胞膜电位的下降.进一步研究发现,MAPKs在METH处理后,通路激活,磷酸化水平显著增高.预孵p38 MAPK抑制剂SB203580后,METH引起凋亡蛋白表达增高的趋势降低.结论 METH可多途径引起神经元损伤,激活MAPKs通路,而p38-MAPK可能参与了METH引起的神经元的损伤.

Effects of methamphetamine acute exposure on neural damage

Objective To explore the neural damage induced by acute exposure to methamphetamine (METH).Methods The mice were administrated with METH,then the stereotyped behavior of mice was evaluated,and spatial recognition memory was analyzed by Y-maze test.In addition,nitric oxide synthase (NOS) activity was detected by kit,and the apoptotic proteins including Bax,Bcl-2,Caspase-3 were assayed by using Western blot.The DNA injury induced by METH was observed by using the comet assay.Moreover,mitochondrial membrane potential was detected to assess the toxic effects of METH on mitochondria by JC-1.With the Western blot assay,the phosphorylation of MAPK signaling pathways were also investigated.Results Acute METH exposure significantly increased the stereotyped behavior in mice,and spatial recognition ability of mice was obviously decreased.On the molecular level,total nitric oxide synthase (TNOS) and induced nitric oxide synthase (iNOS) were increased,and the apoptotic proteins,such as Bax and cleaved caspase-3 were markedly enhanced.With the comet assay,it showed that METH exposure resulted in DNA damage.In parallel,mitochondrial membrane was damaged which manifested as mitochondrial membrane potential decreased.With the western blot,It was further found that METH enhanced the activation of MAPKs.However,p38 MAPK signahng pathway was demonstrated to be the only one factor involved in METH-induced neural damage.Conclusion METH induced neural damage,and MAPK signaling pathways might be involved in this process,since inhibition of p38 MAPK signaling pathway significantly ameliorated METH-induced neural damage.