Cadmium interactions with zinc

Cadmium is nutritionally non-essential, toxic and a ubiquitous environmental pollutant. It is found in leafy vegetables, grains and cereals, and since it is present in substantial amounts in tobacco leaves, cigarette smokers on a packet a day can easily double their cadmium intake. It has a long biological half-life (17-30 years in man), accumulates in liver and kidneys and its toxicity involves principally kidney and bone (Goyer, 1997).While Cd interferes primarily with calcium, it also interacts with zinc and can induce the synthesis of metallothionein. Cadmium bound to metallothionein in liver or kidney is thought to be non-toxic, but cadmium in plasma... 

Atia, A. A., Donia, A. M., and Yousif, A. M. (2003). Synthesis of amine and thio chelating resins and study of their interaction with zinc(ll), cadmium(ll) and mercury(ll) ions in their aqueous solutions. React. Funct. Polym. 56(1), 75-82. 

Casswall TH, Bjorndahl L, Kvist U (1987) Cadmium interacts with the zinc-dependent stability of the human sperm chromatin. J Trace Elem Electrolytes Health Dis 1 85-87... 

Nickel and selenium interact with incandescence on gentle heating [1], as do also sodium and potassium, the latter mildly explosively [2], Uranium [3] and zinc [4] also incandesce when their mixtures with selenium are heated, and platinum sponge incandesces vividly [5], The particle size of cadmium and selenium must be below a critical size to prevent explosions during synthesis of cadmium selenide by heating the elements together. Similar considerations also apply to interaction of cadmium or zinc with sulfur, selenium or tellurium [6], Interaction of powdered tin and selenium at 350° C is extremely exothermic [7],... 

Weis, J.S. 1980. Effect of zinc on regeneration in the fiddler crab Uca pugilator and its interactions with methylmercury and cadmium. Mar. Environ. Res. 3 249-255. 

Metallothionein expression is mainly regulated at the transcriptional level and is induced by various heavy metals, such as zinc. There are seven short sequence motifs located in a region within 200 base pairs upstream of the transcription start site. These cis-acting DNA elements are responsible for heavy metal induction and are thus termed metal responsive elements (MREs) (Stuart et al., 1984). Several regulatory proteins have been cloned which interact with these MREs. One of these, MRE-binding transcription factor-1 (MTF-1), is essential for the transcriptional activation of metallothionein genes by heavy metals like zinc and cadmium (Radtke et al., 1993 Palmiter, 1994 Heuchel et al., 1994 Koiszumi et al., 1999). 

Metals. Nickel, sodium, potassium, uranium, zinc, and platinum sponge interact with selenium with incandescence when gently heated.3-7 The particle size of cadmium and selenium must be below a critical size to prevent explosions when making cadmium selenide this also applies to zinc.8... 

In the diet and at the tissue level, ascorbic acid can interact with mineral nutrients. In the intestine, ascorbic acid enhances the absorption of dietary iron and selenium reduces the absorption of copper, nickel, and manganese but apparently has little effect on zinc or cobalt. Ascorbic acid fails to affect the intestinal absorption of two toxic minerals studied, cadmium and mercury. At the tissue level, iron overload enhances the oxidative catabolism of ascorbic acid. Thus, the level of dietary vitamin C can have important nutritional consequences through a wide range of inhibitory and enhancing interactions with mineral nutrients. 

Interaction with metallothionein is the basis for metabolic interactions between these metals. Metallothionein III is found in the human brain and differs from I and II by having six glutamic acid residues near the terminal part of the protein. Metallothionein III is thought to be a growth inhibitory factor, and its expression is not controlled by metals however, it does bind zinc. Another proposed role for metallothionein III is participation in the utilization of zinc as a neuromodulator, since metallothionein III is present in the neurons that store zinc in their terminal vesicles. Metallothionein IV occurs during differentiation of stratified squamous epithelium, but it is known to have a role in the absorption or toxicity of cadmium. 

Piotrowicz, S. R., Harvey, G. R., Boran, D. A., Weisel, C. P., and Springer-Young, M. (1984). Cadmium, copper, and zinc interactions with marine humus as a function of ligand structure. Mar. Chem., 14, 333-346. 

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