锌对原代培养海马神经元MT mRNA表达的影响

目的　为探讨神经元锌内稳态机制。方法　采用实时荧光定量RT PCR法检测 :原代培养大鼠海马神经元 10 0 μmol L锌诱导后 ,不同时间点 (0、2、4、6和 8h)MT1 MT2 MT3mRNA的表达 ;及 0、5 0、75、10 0、12 5、15 0 μmol L锌诱导 4h后 ,各浓度组MT1 MT2 MT3mRNA的表达。 结果　基础状态下 ,MT的三个异构体在海马神经元内的表达峰度为 :MT3>MT1>MT2 ;在 0～ 10 0 μmol L范围内 ,MT1、MT2mRNA的表达随锌浓度增加而显著增加 ,锌浓度进一步增加时 ,MT1、MT2mRNA的表达进入平台期 ;MT3mRNA的表达随锌浓度的升高而下降 ;锌可显著上调MT1和MT2mRNA表达 ,峰值时间点在 6h左右 ;锌可使MT3mRNA的含量降低约6 0 %。结论　除MT3mRNA外 ,MT1和MT2mRNA在神经元内也有表达 ;象神经胶质细胞一样 ,神经元同样可通过增加MT1和MT2mRNA的表达以维持锌内稳态

Expression of metallothioneins on zinc exposure in rat hippocampal neurons

OBJECTIVE: To study the homeostasis of zinc in central nervous system. METHODS: Expression of MT1/MT2/MT3 on various concentration of zinc exposure (0-150 micromol/L) was determined and their expression on 100 micromol/L zinc exposure after 0, 2, 4, 6 and 8 hours in primary culture rat hippocampal neurons was measured by real-time fluorescent quantitative RT-PCR. RESULTS: Amount of MT3 mRNA was highest followed by MT1 mRNA, MT2 mRNA ranked third. Expression of MT1 and MT2 mRNA could be up-regulated significantly on 75-100 micromol/L zinc exposure, and then, reach to a plateau on 125-150 micromol/L. Their peak mRNA levels appeared at about 6 h after addition of zinc was added. However, the MT3 mRNA was decreased by about 60% after zinc was added 6 h later. CONCLUSION: The results showed that not only the MT3 but also the MT1 and MT2 were involved in the regulation of zinc homeostasis in neurons, just like neuroglial cell do.