Expression of metallothionein in the liver and kidney of rats is influenced by excess dietary histidine

It is well known that excess dietary histidine induces the metabolic change s in copper and zinc. Therefore, this study was carried out to clarify whet her excess dietary histidine alters the gene expressions of metallothionein -l and metallothionein-2 in the liver and kidney. Male rats were fed the co ntrol (ad libitum and pair-fed) or histidine-excess (50 g of (L)-histidine per kg of diet) diet for 0, 1 and 3 days. The levels of liver metallothione in-1 and metallothionein-2 mRNA were markedly lower in the rats fed the his tidine-excess diet as compared to those of the control (ad libitum and pair -fed) diet, when fed for 1 or 3 days. The levels of renal metallothionein-1 and metallothionein-2 mRNA in the rats fed the histidine-excess diet were higher or tended to be higher as compared with the rats fed the control (ad libitum and pair-fed) diet when fed for 1 or 3 days, respectively. At the: same time, hepatic copper content was decreased and renal zinc content was increased by dietary histidine. It thus appears, that such a response on t he level of liver metallothionein mRNA might be related to the contents: of liver copper, but of kidney metallothionein mRNA might be due to the conte nt of zinc. (C) 2001 Elsevier Science Inc. All rights reserved.