Role of Thiocyanate Ion in Metallothionein Induction and in Endogenous Distribution of Essential Elements in the Rat Liver H. HAKAN AYDIN,* HANDAN Ak C ¸ ELIK, AND BILTAN ERSOZ Department of Biochemistry, Ege University School of Medicine, Bornova TR-35100 Izmir, Turkey Received February 12, 2002; Accepted April 15, 2002 ABSTRACT Thiocyanate is the major toxic metabolite of hydrogen cyanide, a toxic substance the organism may be exposed to as a result of cigarette smoking or industrial pollution. The complex interactions existing between metals and metallothionein induction are well known. However, the possible role of thio- cyanate, which is also an anion, has not been established yet. Considering the interactions between metals and the metallothioneins, in this study the rela- tionship between thiocyanate and the in vivo distribution of hepatic metal- lothionein and zinc, copper, iron, calcium, magnesium, and manganese are investigated in rats. This study implies that thiocyanate has, to some extent, an effect on the in vivo expression of metallothionein and endogenous distri- bution of essential elements in rat liver. Elevated levels of metallothionein and changes in hepatic concentrations of essential elements have suggested a role for thiocyanate in cellular metabolism and it might reflect a direct role of thiocyanate on alteration of cellular functional activities. Index Entries: Thiocyanate; metallothionein; copper; zinc; iron; cal- cium; magnesium; manganese. INTRODUCTION Thiocyanate ion (SCN – ) is derived endogenously as a detoxification product of the reaction between cyanide and thiosulfates in the liver. It is Biological Trace Element Research 187 Vol. 90, 2002 © Copyright 2002 by Humana Press Inc. All rights of any nature, whatsoever, reserved. 0163-4984/02/90(1–3)–0187 $20.00 *Author to whom all correspondence and reprint requests should be addressed.