Interaction of Metals (Panel Discussion) (Proceedings of the 10th Symposium on Environmental Pollutants and Toxicology)

Abstract

In the recent two decades, interest has been rising in metal-metal interaction in body. And at present the interactions to find its phenomenon is now being investigated. Therefore in the mechanism of interaction between metals, the hypothesis to explain this mechanism draw only out from these results reported. From these results, the following mechanism should be able to be indicated. (1) Competition in active site. There are competitions between metals against the activated substance or active site in body and those against absorption from a digestive tract, for example, the competition of lead and zinc to ALAD or the suppression by cadmium to the absorption of copper. (2) Formation of complex by metals. When two metals are administered simultaneously, the complex containing these metals is formed in body, and consequently metal toxicity is alleviated. This exsample is investigated in detail in Hg-Se interaction. (3) Induction of metal binding protein. This example can be seen in the induction of metallothionein. A metal which has the ability to induce Zn-thionein is used as pretreatment, and a metal which can replace Zn in Zn-thionein is used as challenge, and the toxicity of challenge metal may be mitigated.