Selenium Bioaccumulation in Freshwater Organisms and Antagonistic Effect against Mercury Assimilation

Metals in tissues of migrant semipalmated sandpipers (Calidris pusilla) from Delaware Bay, New Jersey

“…Some selenoenzyme have an important role in redox signaling, antioxidant defense, thyroid hormone metabolism, and immune responses . The protective effect of selenite on the toxicity of methylmercury may be due to formation of mercuric selenide (HgSe) as a stable, insoluble, and inert compound (Belzile et al, 2009). Selenium also binds to other cations and xenobiotics, such as iron, copper, zinc, and cadmium (reducing its availability to bind to mercury), and is altered by Vitamin E (Beyrouty and Chan, 2006).…”

Methylmercury and selenium speciation in different tissues of beluga whales (Delphinapterus leucas) from the western Canadian Arctic

“…While binding with cysteine is thought to be primarily responsible for MeHg transport across the blood-brain barrier [5,15,16] and hence neurotoxicity, binding with glutathione and Se-containing compounds such as selenocysteine and selenoglutathione is known to detoxify MeHg via demethylation to produce biochemically inert solids HgSe x S 1-x (0 x 1) [13,17]. The protection against MeHg toxicity by thiols and Se depends on the chemical forms and molar ratios of MeHg, S, and Se [6,13,[17][18][19][20], but also may be tissue-specific. That Hg in marine mammals is predominately in the form of MeHg in the muscle [4,8], whereas a significant fraction of inorganic Hg is accumulated in the liver and kidneys [2,4,8], has been well documented.…”

Mercury and selenium in European catfish (Silurus glanis) from Northern Italian Rivers: Can molar ratio be a predictive factor for mercury toxicity in a top predator?

“…It is known that the wide variation of the mercury and selenium content in fish muscle reflects different levels of environmental mercury and selenium pollution (Belzile et al, 2009).…”