Inorganic mercury compounds tissues

There are few reports regarding the respiratory absorption of elemental and inorganic mercury compounds in animals. Elevated levels of mercury were detected in blood and tissues of pregnant or... 

Mercury will cross the placental barrier. In mammalian tissue, organic mercury, especially alkyl mercury, is converted to inorganic forms but not vice versa. Inorganic forms of mercury (not organic forms) induce a metallothionein. Inorganic mercury concentrates mainly in the kidney. Organic mercury compounds, being lipid soluble, concentrate in adipose tissue and the brain. Elimination is primarily in the urine and the feces, with small amounts in breath, sweat, and saliva. 

A variety of effects have been observed in animals treated with toxic doses, but some of these, such as renal damage and anorexia, have not been observed in humans exposed to high doses. The primary tissues of concern in humans are the nervous system and particularly the developing brain, and these have been the main reason for the wide range of epidemiologial studies. Methylmercury passes about ten times more readily through the placenta than other mercury compounds. The dermal absorption of methylmercury is similar to that of inorganic mercury salts. 

Some data indicate that the presence of Se may delay the release of mercury from sample solutions at CV-AAS analysis (see Interferences in CV-AAS ). Yamamoto et al. (1980) observed, at determination of total mercury by CV-AAS according to Magos and Clarkson (1972), a delayed and incomplete release of mercury from blood incubated with inorganic mercury and selenite, as well as from some organ tissues from mice, to which these compounds had been administered simultaneously. The recovery of mercury was normalized when the tissue homogenates were heated (40 °C) with an equal volume of 45 % sodium hydroxide solution. Magos et al. (1984) also found that Se, in different forms of bioavailability, administered to rats, affected the determination of total mercury by the above-mentioned method. They determined a reduction-resistant" fraction of mercury as... 

Inorganic and organic mercury compounds have a strong affinity for thiol chemical groups. Most proteins and aU enzymes contain these groups so that mercury readily is bound to body tissues. Most mercury compounds are potent enzyme inhibitors which affects membrane permeability, which in turn affects nerve conduction and tissue respiration. 

In the global cycle of mercury the accumulation in the aquatic food chain plays a predominant role [6]. Inorganic mercury species are methylated in the water chemically or by microorganisms. The organomercury compounds formed enter the food chain. Caused by bioaccumulation in any of the several steps of the aquatic food chain, the highest levels of mercury can be found in the tissues of large predatory fishes such as marine tuna, swordfish, shark, turbot, or halibut and... 

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