【摘要】 目的　在细胞水平上研究稀土元素 (REE)La、Gd和Ce对培养大鼠细胞的生物学作用及机制。方法　采用同位素示踪、质子激发X荧光分析 (PIXE)结合生化及细胞学等技术观察La对细胞的生物学作用 ,La、Gd及Ce的亚细胞分布及Gd、Ce对细胞钙含量及钙内流的影响。结果　La3 +在 10 -10 (或 10 -9)～ 10 -6mol/L时促进细胞蛋白质合成、线粒体琥珀酸脱氢酶活性增加、DNA合成以及S期细胞比率增加 ,但La3 + 在高剂量时 (10 -4 ～ 10 -3 mol/L)降低平滑肌细胞总蛋白质含量、抑制线粒体琥珀酸脱氢酶活性以及S期细胞比率减少。通过PIXE发现La、Gd、Ce可进入细胞 ,且在核内含量最高 ,其次为胞膜。Gd和Ce使细胞内钙含量增加 ,促进细胞钙内流。结论　①La3 + 对细胞有明显剂量 效应关系 ,在 10 -10 (或 10 -9)～ 10 -6mol/L剂量范围内有促进细胞增殖作用 ,在 10 -4 ～ 10 -3 mol/L时有细胞毒性作用。②REE可进入细胞 ,且在核内富集。③REE可促进细胞外钙进入细胞。更多还原

【Abstract】 Objective To investigate the biological effects and the effecting mechanisms of rare earth elements La,Gd and Ce on cultured rat cells.Methods The biological effects of La 3+ on cultured rat cells and the subcellular distribution of La and Gd and Ce, and the inflow of 45Ca 2+ into the cells and total cellular calcium were measured by isotopic tracing, Proton Induced X Ray Emission Analysis (PIXE) and the techniques of biochemistry and cellular biology.Results La 3+ at the concentration of 10 -10(or 10 -9)～10 -6mol/L significantly increased quantity of incorporation of 3H-TdR into DNA, total cellular protein and the activity of succinic dehydrogenase of mitochondria. The cell cycle analysis showed that the proportions of cells in S phase were accordingly increased acted by La 3+ at above range of concentration. But these values were significantly decreased when concentration of La 3+ raised to 10 -4～10 -3mol/L. It was further discovered that La,Gd,and Ce distributed mostly in the nuclei, and then in membranes. Gd and Ce also promoted the inflow of 45Ca 2+ into the cells and increased the total calcium content in cells.Conclusions ① La 3+ at a wide concentration range of 10 -10( or 10 -9)～10 -6mol/L promotes proliferation of cultured rat cells, but at even higher concentration (10 -4～10 -3mol/L) shows cellular toxicity, and there is a striking dose-effect relationship. ② La,Gd and Ce can enter the cells and mainly distribute in the nuclei. ③ Gd and Ce can promote the inflow of extracellular Ca 2+ into the cells and increase total cellular calcium.更多还原