Metals-Metallothionein Interactions in Biological Systems

Trace elements normally occur in living tissues in low concentrations, even though elements like zinc and copper are essential for growth, health and fertility. Metallothioneins (MTs) play an important role in controlling tissue concentrations of Zn, Cu and Cd and tissue functions. In this paper are reported studies on trace elements and MTs in different animal species. The liver was riche in essential and non-essential metals, due to the physiological role played in the processes of detoxification and storage. Among the investigated metals, Cd reached high concentrations in the kidney of wild birds mainly bound to MT. Preliminary studies that we performed in the mammary gland tumors of dog indicated higher expression of the MT2A isoform. Much remains to be learnt about the role of MTs in organisms and the integrated approach proposed by systems biology could help in this stimulating challenge