重稀碱金属Cs~+跨人红细胞膜行为的研究(英文)

采用原子吸收光谱法检测体外人红细胞摄取Cs+的含量,系统讨论了胞外Cs+浓度,温育时间、温育温度、介质pH值对人红细胞摄取Cs+过程的影响。选用不同离子通道或离子载体的特异性抑制剂进一步探讨Cs+的跨膜途径和机理。结果显示,各实验参数对人红细胞摄取Cs+均有一定的促进作用。Cs+主要借助Na+/K+-泵的主动运输方式跨膜;少量的Cs+能"漏入"细胞,微量的Cs+可以模拟Na+/Li+-反向协同运输的方式跨膜;在允许HCO3-存在的pH环境下,少量Cs+以Cl-/CsCO3-交换的形式通过膜上带3蛋白进入人红细胞;Ca2+通道对Cs+没有通透作用。

The Uptake and Membrane Transport of Cesium in Human Erythrocytes

The uptake of Cs+ by human erythrocytes in vitro was investigated via atomic absorption spectrometry. The results indicate that the metal ions concentration, incubation temperature, incubation hours and media pH all have a positive effect on this cellular uptake process. The mechanism of Cs+ transport into human erythrocytes was briefly discussed. There are mainly four pathways involve in the Cs+ transmembrane activity as far as we concerned: (1) an active transport system mediated by the Na+/K+-ATPase; (2) "leak" process through pores in the membrane proteins; (3)Na+-Cs+ countertransport systems; (4)Cl-/CsCO3- exchanger pathway stimulated by bicarbonate through anion channel(band 3 protein). No inhibition but a little stimulation by Nifedpine in the Cs+ uptake demonstrates that the transport of Cs+ through Ca2+ channel is unavailable.