Selenium with Cadmium

Species Se Cd Blood Liver Kidney Muscle Testes References 

Rats were injected with Cd and Se and the tissue cytosols subjected to gel filtration (Chen et ai, 1975b), The fractions containing the high MV/ peak from the gel filtration step were pooled and divided into various sub samples. Each of these was dialyzed against the reagents indicated. 

Flora et al, (1982) used other biochemical parameters to study the interaction of selenium and cadmium. The administration of cadmium to rats enhanced the urinary excretion of lactic dehydrogenase (LDH), glutamic oxaloacetic transaminase (GOT), and total proteins but decreased the renal activity of GOT and alkaline phosphatase, and renal levels of cadmium, copper, and zinc. Serum GOT and glutamic pyruvic transaminase (GPT) activities and hepatic levels of cadmium and zinc were increased, but the hepatic activities of GOT and GPT were decreased in cadmium-exposed rats. The concomitant administration of selenium reduced most of these cadmium-induced alterations. 

Selenium has been found to slightly increase the absorption of cadmium in rats (Whanger, 1981). This finding is consistent with the data of Welch and House (1980), who labeled lettuce either intrinsically or extrinsically with and Se and fed it to rats as a single meal. 

Absorption of increased with increased selenium levels in the meal, particularly in rats fed intrinsically labeled lettuce leaves. Neither the source of Cd nor the selenium level in the meal affected the biological half-life of ° Cd. The biological half-life of cadmium is extremely long, and there is no known way to reverse the damage due to this element. 

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Whanger PD. 1985. Metabolic interactions of selenium with cadmium, mercury, and silver. Adv Nutr Res 7 221-250. 

Magos, L., and M. Webb. 1980. The interaction of selenium with cadmium and mercury. Crit. Rev. Toxicol. 8(1) 1-42. 

Magos L, Webb M. 1980. The interactions of selenium with cadmium and mercury. CRC Crit Rev Toxicol (Nov) 1980 1-42. 

Metabolic Interactions of Selenium with Cadmium, Mercury, and Silver... 

Various proposals have been presented to explain the interaction of selenium with heavy metals. However, no single one appears to explain the mechanism of interaction with all heavy metals. It appears that there are several mechanisms involved in this interaction and that more than one could be involved with a particular metal. It is clear that selenium does not protect animals against heavy metal toxicity by increasing their excretion instead, it causes an increased retention of metals (Parizek et al, 1971 Wagner et al., 1975 Diplock, 1976 Ganther, 1978 Whanger, 1981). A summary of the proposed interactions of selenium with cadmium, mercury, and silver is presented in Fig. 1. 

Naganuma et al., 1980). Selenide has been found to react with methyl-mercury in vitro to form bis(methylmercuric)selenide (reaction 10), but either protein sulfhydryl groups or reduced glutathione was needed when other chemical forms of selenium were used (Iwata et al., 1981). The detection of selenide, although at very low levels, in the tissues of mice treated with selenium and methylmercury (Naganuma et al., 1980) is evidence that this reaction occurs in animals. Hence, there are several possible mechanisms of interaction of selenium with cadmium, mercury, and silver, and many physiological aspects of this interaction still to be elucidated. 

Although it is only slowly oxidized in moist air at ambient temperature, cadmium forms a fume of brown-colored cadmium oxide [1306-19-0] CdO, when heated in air. Other elements which react readily with cadmium metal upon heating include the halogens, phosphoms, selenium, sulfur, and tellurium. The standard reduction potential for the reaction... 

The cadmium red pigment intermediate is obtained as a precipitate which is filtered off, washed, and calcined at approx. 600 °C. As with cadmium yellow, calcination yields the red pigment and determines the particle size, particle size distribution, and color shade. Analogously to the cadmium yellow process, cadmium red can be produced by direct reaction of cadmium oxide or cadmium carbonate with sulfur and the required amount of selenium at approx. 600 °C. 

Human blood levels of selenium are reported to correlate somewhat with soil concentrations of the element (94). In addition, human ingestion of selenized vegetables and grain has resulted in signs of selenium toxicity (146). Ingestion of rice contaminated with cadmium from the effluent of a mining operation was hypothesized as the etiological factor in Itai-Itai disease in man (32). 

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... 

Gold nanorods were prepared by the photochemical procedure of Kim et al. [6]. Gold nanocrystals with an average diameter of 2.5 nm were obtained by the reduction of chlo-roaurate ion (0.55 ml of 25 mM aqueous solution) by partially hydrolyzed tetrakis (hydroxymethyl) phosphonium chloride (THPC) [7], CdSe nanocrystals were prepared by the solvothermal procedure starting with cadmium stearate, selenium and tetralin in toluene [8]. SWNTs prepared by the electric arc method with a Y2O3 + Ni catalyst, were purified by acid and hydrogen treatments [9]. 

The concentrations of several trace elements increase sharply with increased time, and they continue to increase even after most of the other elemental concentrations have reached steady-state values. These elements, arsenic, selenium, and cadmium, are associated with sulfide mineral phases, possibly as sulfides (or selenides). The mobilization of these elements may depend not only on the pH of the leachate, but also on the rate at which the respective mineral phases are oxidized. 

A wide variety of interactions of selenium with essential and nonessential elements, vitamins, xenobiotics, and sulfur-containing amino acids have been demonstrated in numerous studies. Selenium has been reported to reduce the toxicity of many metals including mercury, cadmium, lead, silver, and to some extent, copper (Frost 1972). Most forms of selenium and arsenic interact to reduce the toxicity of both elements (Levander 1977). Because of selenium s role in the antioxidant glutathione peroxidase enzymes, selenium also reduces the toxicity of metals in vitamin E-deficient animals (Diplock et al. 1967). 

Microcomponents Inorganic microcomponents cover almost the entire periodic table. Here we discuss only those elements that are determined most frequently beryllium, vanadium, chromium, cobalt, nickel, copper, zinc, arsenic, selenium, silver, cadmium, antimony, barium, and lead. The techniques of choice are FAAS, graphite furnace-AAS (GF-AAS), ICP, and hydride generation-AAS (HG-AAS). An ultrasonic nebulizer has recently become commercially available for FAAS and ICP-AES, which decreases the lower determination limits. ICP-mass spectrometry (ICP-MS) is a recent development in which ionization is combined with sensitive mass discrimination. In a further development a graphite furnace is used in front of the ICP-MS. Selective evaporation of elements in the graphite furnace reduces the influence of highly interfering matrices. ICP-MS is expensive, which deters its widespread use. 

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