The toxicity of<unk>  sources can be expected to depend on its nature, i.e., salts vs. organomercury compounds vs. elemental<unk> . The primary mechanism of<unk>  toxicity involves its irreversible inhibition of selenoenzymes, such as thioredoxin reductase (IC50 = 9 nM). Although it has many functions, thioredoxin reductase restores vitamins C and E, as well as a number of other important antioxidant molecules, back into their reduced forms, enabling them to counteract oxidative damage. Since the rate of oxygen consumption is particularly high in brain tissues, production of reactive oxygen species (ROS) is accentuated in these vital cells, making them particularly vulnerable to oxidative damage and especially dependent upon the antioxidant protection provided by selenoenzymes. High<unk>  exposures deplete the amount of cellular selenium available for the biosynthesis of thioredoxin reductase and other selenoenzymes that prevent and reverse oxidative damage, which, if the depletion is severe and long lasting, results in brain cell dysfunctions that can ultimately cause death.<unk>  in its various forms is particularly harmful to fetuses as an environmental toxin in pregnancy, as well as to infants. Women who have been exposed to<unk>  in substantial excess of dietary selenium intakes during pregnancy are at risk of giving birth to children with serious birth defects.<unk>  exposures in excess of dietary selenium intakes in young children can have severe neurological consequences, preventing nerve sheaths from forming properly. Exposure to methylmercury causes increased levels of antibodies sent to myelin basic protein (MBP), which is involved in the myelination of neurons, and glial fibrillary acidic protein (GFAP), which is essential to many central nervous system (CNS). This causes an autoimmmune response against MBP and GFAP and results in the degradation of neural myelin and general decline in function of the CNS.
Mercury poisoning
Minamata disease
Mercury Poisoning
Niigata Minamata disease
Cobalt poisoning
Childhood disintegrative disorder
Cadmium poisoning
Lead poisoning