The effects of various heavy metal ions (such as Hg(2+), Cd(2+), Cu(2+) and Zn(2+)) on mitochondrial membrane with specific reference to K(+) compart mentation

The effects of various heavy metal ions such as Hg(2+), Cd(2+), Cu(2+) and Zn(2+) on mitochondrial membrane were investigated and the following results were obtained; 1) Hg(2+), Cd(2+), Cu(2+) and Zn(2+) released the potassium ion from the mitochondria with the increasing level of an affinity to SH compounds. 2) The release of K(+) by Cd(2+) and Zn(2+) was inhibited in the presence of Mg(2+), but the release of K(+) by Hg(2+) and Cu(2+) was not affected. 3) In the presence of ImM DTT, the release of K(+) by all of these metal ions was completely inhibited.4) The K+ release by Hg(2+) and Cu(2+) was inhibited by DTNB or PCMB which bound prefencially the thiol component of membrane protein, but the release by Cd(2+) and Zn(2+) was not inhibited by these reagents. 5) The release of K(+) decoupled the oxidative phosphorylation by treatment of the heavy metal ions