Abstract: It was well known that high doses of lanthanons do harm to animal cells in various ways.In this paper the reactions between the lanthanons and the metallothionein(MT)──a heavy metal detoxication protein was studied.The experimental data supported the result that MTcan't bind to lanthanons either in vivo or in votro.In addition,the study proved that lanthanons can not introduce the synthesis of MTin rat liver,even when high doses(0.002%～0.0032%) lanthanum and europium salts were used.The possible reasons were discussed in this paper.

Key words: Lanthanons, Metallothionein, Transferrin