中文摘要：

目的 研究铅暴露对海马神经元代谢性谷氨酸受体5亚型（mGluR5）mRNA和蛋白水平表达的影响。方法 对原代培养3d的胎鼠海马神经元分为4组，分别为加入氯化铅溶液终浓度为10^-8 mol／L、10^-6 mol／L、10^-4mol／L的各铅暴露组和空白对照组。用实时荧光定量RT—PCR和Westernblot方法检测每组神经元mGluR5 mRNA和蛋白水平的表达。结果 铅暴露组海马神经元mGluR5mRNA表达较正常对照组下调，且随铅暴露浓度升高下调越明显。10^-8mol／LPb^2＋ 组、10^-6 mol／LPb^2＋组、10^-4 mol／LPb^2＋组mGluR5 mRNA表达量与正常对照组比值分别为0．724、0．421、0．321。Westernblot结果显示铅暴露组mGluR5蛋白表达量低于正常对照组，同样呈剂量效应关系，差异有统计学意义（F=77．966，P〈0．001）。结论 铅暴露导致培养的大鼠海马神经元mGluR5基因mRNA和蛋白表达下降，且铅暴露剂量与下降幅度有一定相关性。

英文摘要：

Objective To study the effects on the expression of mGluR5 mRNA and protein levels in primarily cultured hippocampal neurons after lead exposure. Methods Primary embryonic rat hippocampal neuronal culture was prepared. On the 3^rd day of incubation, lead chloride solution was added into medium to produce four different lead exposure levels： 0, 1× 10^-8 mol/L, 1 × 10^-6mol/L, 1 × 10^-4 mol/L Pb^2＋. After 10 days of incubation, the neurons were collected to measure the alteration of mGluR5 mRNA expression by real-time fluorescent quantity PCR and the expression of mGluR5 in protein level by Westernblot. Results The studies revealed that mGluR5 mRNA expression was down-regulated after lead exposure in a dose-dependent manner. The mGluP,.5 mRNA expression of the lower lead-exposed neurons （Pb^2＋ 10^-8 mol/L）, the medium lead-exposed neurons（ Pb^2＋ 10^-6 mol/L）, the higher lead-exposed neurons （Pb^2＋ 10^-4 mol/L） were 0. 724, 0. 421, 0. 321 times less than that of the controls, respectively. The Westernblot demonstrated that mGluR5 expression in protein level should be decreased after lead exposure. Conclusion The expression of mGluR5 in mRNA and protein levels should be down-regulated after lead exposure at different lead levels in a dose-dependent manner.