Inhibition selenium

Monovalent gold salts impacted metabolism of seleifium, copper, and zinc. Intravenous Au" " may adversely affect the availability of seleifium for synthesis of selenoenzymes. Rats given gold sodium thiomalate iv at 25.0 or 50.0 xmol/kg BW had sigifificantly altered seleifium deposition, as measured by radioselenium-75. These effects included the almost complete cessation of Se exhalation as dimethyl sulfide and the accumulation of Se in blood plasma. Direct chemical reaction with nucleophilic selenium metabolites in the body may underlie these alterations. Auranofin inhibited selenium-glutathione peroxidase in bovine erythrocytes this enzyme... 

One area of research is the replacement of sulfur with selenium to enhance the potency of organic compounds in pharmaceutical apphcations. This has seldom been successflil and often the toxicity is increased. There are some exceptions, eg, selenazofurin, phenylaminoethyl selenide, ebselen, and selenotifen (64). Selenazofurin is a cytotoxic compound having antitumor properties, phenyl aminoethyl selenide is used to reduce hypertension, ebselen inhibits a variety of inflammatory and tissue damaging reactions, and selenotifen is an antiallergic agent. 

The wide substrate tolerance of lipases is demonstrated by the resolution of organometallic substrates [129-131]. The presence of tin, selenium, or tellurium in the structure of secondary alcohols does not inhibit the lipase activity and enantiopure organometallic alcohols were obtained by acylation in organic media (Figure 6.48). 

Hu, M.-L., Dillard, C.J. and Tappel, A.L. (1988) Aurofhioglucose effect on sulfhydryls and glutathione-metabolizing enzymes in vivo inhibition of selenium-dependent glutathione peroxidase. Research Communications in Chemical Pathology and Pharmacology, 59,... 

Roberts, J. and Shaw, C.F. Ill (1998) Inhibition of erythrocyte selenium-glutathione peroxidase by auranofin analogs and metabolites. Biochemical Pharmacology, 55, 1291-1299. 

Many dietary supplements have antiplatelet activity, which may increase the risk of bleeding when used concurrently with anticoagulants. Feverfew inhibits cyclooxygenase and phospholipase A2 and may interact with anticoagulants and potentiate the antiplatelet effect of aspirin. Other supplements that possess antiplatelet activity include but are not limited to garlic, ginkgo, vitamin E, vitamin A, and selenium. 

Lee, B., el al. (2002). Prostaglandin D synthase in the prenatal ovine brain and effects of its inhibition with selenium chloride on fetal sleep/wake activity in utero. 

Matsumura, H., et al. (1991). Inhibition of sleep in rats by inorganic selenium... 

The effects of antioxidants on protein oxidation were also studied in animal experiments. Barja et al. [73] demonstrated that feeding guinea pigs with vitamin C decreased endogenous protein oxidative damage in the liver. Administration of the mixture of antioxidants containing Trolox C, ascorbic palmitate, acetylcysteine, (3-carotene, ubiquinones 9 and 10, and (+)-catechin in addition to vitamin E and selenium to rats inhibited heme protein oxidation of kidney homogenates more efficiently than vitamin E + selenium [74]. 

Phenylchalcogenyl-l-naphthols with sulfur (91), selenium (92), and tellurium (93) were prepared, as was the methylene analog (90), and their oxidation potentials determined by CV vs. SCE. All were irreversible, and only the Te compound 93 (1.00 V) differed significantly from the other three ( 1.25 V) (Table 9). It is likely that the naphthol moiety is controlling the oxidation potential of 90-92. Interestingly, only 93 showed significant ability to inhibit lipid peroxidation in a... 

Borek, C., Ong, A., Mason, H., Donahue, L, and Biaglow, J. E., 1986, Selenium and vitamin E inhibit radiogenic and chemically induced transformation in vitro via different mechanisms, Proc. Natl. Acad. Sci. USA 83 1490-1494. 

Epidemiological studies in humans do not suggest an association between excess exposure to selenium and cancer." Low levels of intake, however, have been associated with an increased risk of developing many kinds of cancers. With the exception of selenium sulfide, most animal studies have shown that selenium compounds inhibit tumorigenesis." High doses of selenium sulfide administered by gavage caused liver tumors in rats and lung... 

Nutritional status can also influence the toxic potency of carbon tetrachloride. Animal studies have clearly demonstrated that brief fasting or consumption of diets low in antioxidants (vitamin E, selenium, methionine) can lead to increased carbon tetrachloride hepatotoxicity. The same may be true for humans, although this is not known for certain. Another aspect of nutritional status affecting carbon tetrachloride toxicity is hepatic energy status. Hepatic ATP levels might influence the ultimate outcome of toxicity (low levels may inhibit recovery mechanisms). 

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