铅对培养海马神经细胞生长和nNOS表达的影响

目的研究不同剂量醋酸铅对原代培养的海马神经细胞生长和神经元型一氧化氮合酶(nNOS)表达的影响。方法将孕18dSD大鼠麻醉后剖腹取出胎鼠,采用海马神经细胞培养建立细胞模型,醋酸铅的染毒浓度分别为10-5mol/L(高剂量组)、10-7mol/L(中剂量组)、10-9mol/L(低剂量组),对照组给予等量培养液。染毒24h后用免疫组织化学法检测神经细胞球和单个神经细胞nNOS蛋白的表达。结果各剂量组对海马神经细胞胞体、轴突突起长度和细胞间连接均未见明显影响。高剂量组和中剂量组海马神经细胞球和散在的神经细胞nNOS的表达明显下降,与对照组相比差异具有统计学意义(P<0.05)。低剂量组海马神经细胞球和散在的神经细胞nNOS的表达较对照组有所下降,与对照组相比差异没有统计学意义(P>0.05)。结论低剂量铅下调培养的海马神经细胞nNOS的表达,这种下调作用具有剂量依赖性。

Effect of Lead Acetate on Growth of Cultured Hippocampus Neural Cells and Expression of nNOS

Objective To investigate the effect of lead acetate on the growth of cultured hippocampal neural cells and expression of nNOS.Methods The hippocampal neural cells were isolated from 18-day rat embryos and cultured in the DMEM/F12 media containing 10% fetal calf serum.The cultures were exposed to lead acetate with 3 different levels of 10-5mol/L,10-7mol/L and 10-9mol/L respectively.After 24h cultivation,nNOS was detected by immunohistochemistry in both neural spheres and sparse cells.Results No significant changes were observed in the size of cell body,length of axiones and connections between cells in all cultures exposed to lead acetate.However,high and middle dosages of lead acetate led to significant down-regulation of nNOS expression in both neural spheres and sparse cells as compared with the controls(P<0.05);furthermore,exposure to low dosage of lead acetate did casue the down-regulation of nNOS expression,but not reached statistical significance(P>0.05).Conclusion Lead acetate can down-regulate expression of nNOS in cultured hippocampal neural cells in a dose-dependent manner.