The Roles of Serum Selenium and Selenoproteins on Mercury Toxicity in Environmental and Occupational Exposure

Abstract

Many studies have found that mercury (Hg) exposure is associated with selenium (Se) accumulation in vivo. However, human studies are limited. To study the interaction between Se and Hg, we investigated the total Se and Hg concentrations in body fluids and serum Se-containing proteins in individuals exposed to high concentrations of Hg. Our objective was to elucidate the possible roles of serum Se and selenoproteins in transporting and binding Hg in human populations. We collected data from 72 subjects: 35 had very low Hg exposure as evidenced by mean Hg concentrations of 0.91 and 1.25 ng/mL measured in serum and urine, respectively; 37 had high exposure (mean Hg concentrations of 38.5 and 86.8 ng/mL measured in serum and urine, respectively). An association between Se and Hg was found in urine (r = 0.625; p < 0.001) but not in serum. Hg exposure may affect Se concentrations and selenoprotein distribution in human serum. Expression of both selenoprotein P and glutathione peroxidase (GSH-Px) was greatly increased in Hg miners. These increases were accompanied by elevated Se concentrations in serum. In addition, selenoprotein P bound more Hg at higher Hg exposure concentrations. Biochemical observations revealed that both GSH-Px activity and malondialdehyde concentrations increased in serum of the Hg-exposed group. This study aids in the understanding of the interaction between Se and Hg. Selenoproteins play two important roles in protecting against Hg toxicity. First, they may bind more Hg through their highly reactive selenol group, and second, their antioxidative properties help eliminate the reactive oxygen species induced by Hg in vivo.

Maternal fish and other seafood intakes during pregnancy and child neurodevelopment at age 4 years

“…Alternatively, it is also possible that adverse effects of MeHg exposure may be exacerbated in the presence of low levels of Se, which have been reported in some Spanish populations (24,53) . Se is thought to reduce tissue accumulation of Hg (54) and is involved in activating selenoproteins believed to reduce Hg toxicity (55) .…”

Heavy Metal and Selenium Concentrations in Liver Tissue From Wild American Alligator (Alligator Mississippiensis) Livers Near Charleston, South Carolina

“…Alligators that exhibited relatively higher concentrations of Hg also showed higher concentrations of selenium. Selenium is thought to be an important component of detoxification of methyl-Hg (Martoja and Berry, 1980;Chen et al, 2006). Positive relationships between Hg and Se have been documented in crocodiles (Almli et al, 2005).…”

Distribution and Dynamic Pathway of Selenium Species in Selenium-deficient Mice Injected with 82Se-enriched Selenite

“…Selenium (Se) is an essential element for humans and other animals with a narrow adequate range between deficient and excessive doses, and has functions in antioxidant effect, 1 alleviating the toxicity of heavy metals, 2 and sperm production. 3 Se deficiency induces arterial sclerosis, 4 cardiac myopathy, 5 and infectious disease.…”