Selenium interaction with silver

No other studies were located regarding additive or synergistic toxic interactions of silver with any other substance. However, exposure to moderate-to-high silver levels (130-1000 ppm) in rats with dietary deficiencies such as vitamin E alone (Bunyan et al. 1968 Grasso et al. 1969) or vitamin E and selenium (Van Vleet 1976 Van Vleet et al. 1981) can cause moderate-to-severe liver necrosis. 

Rungby J. 1987. Silver-induced lipid peroxidation in mice Interactions with selenium and nickel. Toxicology 45 135-142. 

Copper interacts with numerous compounds normally found in natural waters. The amounts of the various copper compounds and complexes present in solution depend on water pH, temperature, and alkalinity and on the concentrations of bicarbonate, sulfide, and organic ligands. In animals, copper interacts with essential trace elements such as iron, zinc, molybdenum, manganese, nickel, and selenium and also with nonessential elements including silver, cadmium, mercury, and lead interactions may be either beneficial or harmful to the organism. The patterns of copper accumulation, metabolism, and toxicity from these interactions frequently differ from those produced by copper alone. Acknowledgment of these interactions is essential for understanding copper toxicokinetics. 

The metabolic interactions of selenium with silver and their influence... 

Silver accumulated in the liver with each increase of dietary silver, and this significantly increased hepatic copper and iron content (Table VI). However, silver had no influence on the zinc content of the liver. Dietary selenium significantly increased the silver content of the liver, consistent with the results of Wagner et al. (1975). The metabolic interaction of silver with copper in the rat is in agreement with findings by others using the chick (Hill et al, 1964 Peterson and Jensen, 1975b). 

Present data indicate that silver has no effect on zinc in any rat tissue. This finding is in agreement with work with the chick (Hill and Matrone, 1970). Since the Ag ion is like the cupric ion and unlike the cuprous and zinc ions, it is proposed that divalent silver is the metabolic active form. Furthermore, the data of Tables V-VII indicate that the effect of silver on copper and iron metabolism, and the interaction of selenium with silver, are tissue dependent. Hence, there appears to be a metabolic interaction between selenium and silver in some tissues, and this interaction influences copper and iron levels. 

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. 

Antimony, arsenic, selenium, tellurium, iridium, iron, molybdenum, osmium, potassium, rhodium, tungsten (and when primed with charcoal,) aluminium, copper, lead, magnesium, silver, tin, zinc. Interaction of lithium or calcium with chlorine tri- or penta-fluorides is hypergolic and particularly energetic. 

Ganther HE. 1980. Interactions of vitamin E and selenium with mercury and silver. Ann NY Acad Sci 355 212-226. 

Ridlington JW, Whanger PD. 1981. Interactions of selenium and antioxidants with mercury, cadmium and silver. Fundam Appl Toxicol 1 368-375. 

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

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). 

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

Slightly different effects of silver on the renal mineral content were observed (Table VII). In contrast to the liver, silver had no significant effect on renal copper and iron levels. As for the liver, silver had no effect on renal zinc levels. Also consistent with the liver, silver accumulated in the kidneys, and selenium caused a significant increase in this accumulation. However, in contrast to the liver, there was a significant interaction between selenium and silver with respect to the accumulation of silver in this organ. This indicates that only a combination of selenium and silver brings about this effect. 

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. 

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