运用流式细胞仪和膜片钳技术研究La3+,Gd3+,Yb3+三种稀土离子诱导大鼠背根神经元DRG凋亡以及膜上钾离子通道的影响。结果表明:10,100,1000μmol.L-1LaCl3和GdCl3处理DRG神经元96 h,细胞不出现凋亡;YbCl3处理96 h,细胞的凋亡率明显递增。胞外La3+,Gd3+,Yb3+抑制瞬间外向钾电流IA,使IA的激活和失活过程都显著右移,抑制和右移的程度La3+最弱,Gd3+次之,Yb3+最强;胞内的La3+,Gd3+,Yb3+抑制延迟整流钾电流IK,抑制的程度也呈增长趋势。稀土离子在胞内外的结合位点不同;Yb3+较La3+和Gd3+的神经毒性强。
Apoptosis of rat dorsal root ganglion(DRG) neurons induced by La3+,Gd3+ and Yb3+,as well as their influence on K+-channels were studied by flow cytometry and whole-cell patch clamp method.The results showed that the apoptosis rate did not change after the DRG neurons were treated with LaCl3 and GdCl3 of 10,100 and 1000 μmol·L-1 for 96 h,while the apoptosis rate with three concentration groups of YbCl3 increased significant.The La3+,Gd3+ and Yb3+ of 100 μmol·L-1 in the extracellular solution played a dominant role in inhibiting the transient outward potassium current(IA).Both activation and inactivation of IA shifted significantly to the right,where La3+ had the weakest effect while Yb3+ had the strongest.The La3+,Gd3+ and Yb3+ in the intracellular solution,however,only inhibited the rectifier potassium current while the effect of inhibition also displayed augmented tendency.In conclusion,Yb3+ had relatively more serious neurotoxicity than La3+ and Gd3+.