Ni^(2+)和Cd^(2+)跨人红细胞膜的比较研究

Comparative Studies on the Transport Across Human Erythrocyte Membrane by Metal Ions Ni^(2+) and Cd^(2+) with Different Configurations of Electron

The rate constants of transmembrane transport of Ni 2+ and Cd 2+ with the same charge and different configurations of electron were determined in this experiment, and their first-order kinetic rate constant is as follows: for Ni 2+, k(Ni 2+)=0.002 0 h -1, and for Cd 2+, k(Cd 2+)=0.021 h -1. There are large differences between their rates of transmemebrane transport. The mechanisms of transmembrane transport of Ni 2+ and Cd 2+ are studied at the same time. The influences of the concentration of metal ions, pH of solution and the transport inhibitor on the uptake of Ni 2+ and Cd 2+ by human erythrocytes have been studied. The results show that Ni 2+ ions pass through the membrane by passive diffusion, while for Cd 2+, some of them are transported by the anion channel, the others by passive diffusion. Because there are different configurations of electron in the two ions, there are large difference in action of them with protein in the membrane of human erythrocytes.