Effect of zinc supplementation on metallothionein, copper, and zinc concentration in various tissues of copper-loaded rats

Abstract

The present study was designed to investigate the effects of Zn administration on metallothionein concentrations in the liver, kidney, and intestine of copper-loaded rats. Male CD rats were fed a diet containing 12 mg Cu and 67 mg Zn/kg body wt. They were divided into either acute or chronic experimental protocols. Rats undergoing acute experiments received daily ip injections of either Cu (3 mg/kg body wt) or Zn (10 mg/kg body wt) for 3 d. Chronic experiments were carried out on rats receiving Cu ip injections on d 1, 2, 3, 10, 17, and 24, Cu injections plus a Zn-supplemented diet containing 5 g Zn/kg solid diet, or a Zn-supplemented diet alone. Rats injected Zn or Cu had increased MT concentrations in liver and kidney. Zn produced the most important effects and the liver was the most responsive organ. Rats fed a Zn-supplemented diet had significantly higher MT concentrations in liver and intestine with respect to controls. Increased MT synthesis in the liver may contribute to copper detoxification; the hypothesis of copper entrapment in enterocytes cannot be confirmed.

Biological responses related to agonistic, antagonistic and synergistic interactions of chemical species

“…Also, selenite stimulated the gastrointestinal excretion of arsenic in experiments similar to those in which arsenic stimulated the gastrointestinal excretion of selenium [34]. Thus, As/Cd S Humans More pronounced renal toxicity than exposure to each of the agents alone [198] S Rats Induce lipid peroxidation, glutathione and metallothionein, as well as the redistribution of essential elements [199] As/Zn A Rats Zn counteracts As-induced abnormal blood lipids [96] A Rats Zn prevents arsenic-induced tissue oxidative stress [200] As/P A Human cells As perturbs phospholipid bilayer structures, modifying their thermotropic behaviour [201] A Bacterial systems Bacterium that can grow with As instead of P [101] A Zn decreases Cu concentrations in kidney and liver [232] A Rats Zn competes with Cu [233] A Humans and rats Zn influences Cu-induced lipid peroxidation [234] Cu/Fe A Arthropods and molluscs Fe substitutes Cu in some enzyme families [100] selenium deficiency can decrease the excretion of inorganic and organic arsenic in animal models [108], and may induce the accumulation of As in mice liver [109]. On the other hand, selenium sufficiency increases the excretion of arsenic in pregnant women [110] and mice [108].…”

Metal and metallothionein distribution in different tissues of the Mediterranean clam Venerupis philippinarum during copper treatment and detoxification

“…Zn competes with other transition metals such as Cu for binding sites. Some studies have reported the Zn ability of interacting with Cu decreasing metal content and retarding oxidative process within cells and tissues (Irato et al, 1996;Irato and Albergoni, 2005;Santon et al, 2006;Formigari et al, 2007). Zn antagonizes in various systems the catalytic properties of the redox-active transition metals Fe and Cu by reducing their ability to generate hydroxyl radical and superoxide (Formigari et al, 2008).…”

Zinc Therapy Increases Duodenal Concentrations of Metallothionein and Iron in Wilson's Disease Patients

“…Although all the mechanisms of action have not been completely clarified, competition for absorption on the luminal side of the intestinal epithelium (7)(8)(9)(10), and/or induced synthesis of metallothioneins (11,12) have been identified. MT synthesis may also be stimulated by other trace elements such as Cd, Cu, Hg, Au, Ag, Co, Ni, and Bi, or by inflammatory conditions (13).…”