慢性低水平铅暴露对发育期大鼠海马NMDAR-1 mRNA表达的影响

目的：探讨发育期低水平铅暴露对大鼠学习记忆影响的分子机制。方法：采用原位杂交技术，研究低水平铅后发育期海马NMDA受体亚单位1（NMDAR－1）mRNA表达的变化。结果：铅暴露组大鼠海马区锥体细胞层NMDAR－1 mRNA与对照组相比在16d时CA1区、CA3区分别增加18．75％和13．2％（P＜0．05），而在齿状回颗粒细胞层表达却降低14．29％（P＜0．01）；在32、64d除齿状回野粒细胞层表达降低9．67％、10．67％外（P＜0．01）外，其余各海马区未见有明显的光密度变化。结论：发育期铅暴露能导致NMDAR－1 mRNA表达的改变，进而影响NMDAR－1的表达，这可能是铅暴露影响学习记忆的分子机制之一。

Effects of chronic low lead exposure on NMDA receptor subunit 1 mRNA in hippocampus in rats at the developmental stage

Objective To explore the effect of chronic low lead exposure on molecular pathological mechanisms of learning and memory of rats at the developmental stage Methods The changes of N methyl D aspartate receptor 1 (NMDAR 1) mRNA expression in rat hippocampus were observed by using digoxigenin labled anti sense oligonucleotide probes in situ hybridization technique Results The changes in NMDAR 1 mRNA levels in Pb exposed rat hippocampus were found to be dependent upon the developmental period of exposure and the region of the hippocampus analyzed Hippocampal NMDAR 1 mRNA levels increased significantly in the CA1 (18 75%) and CA3 (13 2%) ( P <0 05) pyramidal cells from 16 day old Pb exposed rats, but dentate gyrus NMDAR 1 mRNA decreased by 14 29% at the same same time ( P <0 01) At 32nd day and 64th day, no changes were found except for a DG decrease of 9 67%, 10 67%( P <0 01) Conclusion NMDAR 1 mRNA expression in developing rats is altered by chronic low lead exposure, which might be a molecular mechanism for the persistent cognitive deficits that result from developmental exposure to Pb 2+