Effect of various amounts of selenium on the metabolism of mercuric chloride in mice

Male ddY mice were given one injection of (1) mercury (mercuric chloride) simultaneously with various doses of selenium (sodium selenite), (2) mercury alone, or (3) various doses of selenium alone. The interaction between mercury and selenium in the liver and kidneys at 1, 5, 24, 120, and 240 hr after administration was investigated. The concentrations of mercury in the liver of mice receiving mercury and selenium simultaneously were higher than those after administration of mercury alone, while the concentrations of mercury in the kidney decreased markedly over a 1-120 hr period after administration, depending on the dose of selenium administered simultaneously with mercury. Clearly, selenium had a different effect on the accumulation of mercury in the liver and kidneys. Subcellular distribution studies revealed that mercury and selenium which were administered simultaneously were incorporated into the crude nuclear and mitochondrial fractions as stable complexes. The transport of these complexes to the kidneys seems to be limited. In addition, gel filtration of supernatant fractions of liver and kidney through a Sephadex G-75 column indicated that the proportion of mercury bound to metallothionein fraction decreased depending on the dose of selenium administered simultaneously with the mercury. This reduction was attributed to the decreased synthesis of mercury-thionein due to a reduction in the activity of Hg2+ which results from binding between mercury and selenium in the cells.