Abstract:This review was undertaken to establish what might be the maximum safe dose of selenium that could be administered to man in studies on the use of the element in cancer prevention. The early history of selenium poisoning is briefly summarized. The literature on clinical signs and toxicity data for acute and for chronic selenosis in farm and experimental animals is discussed. Several cases of acute selenosis in man are reviewed, and a number of reports on chronic selenosis in man are reviewed and evaluated. Bas… Show more
“…Antimony (Sb), As, U, and Cd have apparent carcinogenic activity, whereas Cd, As, and U are nephrotoxic (EPA IRIS;Fowler, 1993;Madden and Fowler, 2000;Hornung, 2001;Sanchez et al, 2001;De Boeck et al, 2004;Taulan et al, 2004;Smith et al, 2006). Excessive selenium (Se) exposure may produce gastrointestinal symptoms, liver dysfunction, loss of hair and nails, nervous system impairment (Olson, 1986), and hematological and thyroid effects (Kumar et al, 2008). Metals may also interact to produce effects on target organ systems.…”
Blood lead concentrations are higher in young children than in other age groups, whereas little is known regarding concentrations of other metals in young children. We measured the concentrations of a suite of metals in the blood of children 1-6 years of age, and assessed potential differences by age, season, or region of Maine. We used blood submitted to the Maine State Health and Environmental Testing Laboratory for blood lead analysis to determine the concentrations of arsenic (As), antimony (Sb), cadmium (Cd), manganese (Mn), mercury (Hg), selenium (Se), tin (Sn), and uranium (U) in 1350 children 1-6 years of age. The essential metals Mn and Se were detected in all samples, and As and Sb were detected in 490% of samples. Hg was detected in approximately 60% of samples. U and Cd were less often detected in blood samples, at approximately 30% and 10% of samples, respectively. Sn was not detected in any sample. Concentrations of As, Hg, and Se increased with age, whereas Sb decreased with age. Concentrations also varied by season and region for some though not all metals. Significant pairwise correlations were observed for a number of metals. Blood is a reasonable compartment for measurement of most of these metals in young children. The use of convenience samples provided a cost-effective mechanism for assessing exposure of young children in Maine.
“…Antimony (Sb), As, U, and Cd have apparent carcinogenic activity, whereas Cd, As, and U are nephrotoxic (EPA IRIS;Fowler, 1993;Madden and Fowler, 2000;Hornung, 2001;Sanchez et al, 2001;De Boeck et al, 2004;Taulan et al, 2004;Smith et al, 2006). Excessive selenium (Se) exposure may produce gastrointestinal symptoms, liver dysfunction, loss of hair and nails, nervous system impairment (Olson, 1986), and hematological and thyroid effects (Kumar et al, 2008). Metals may also interact to produce effects on target organ systems.…”
Blood lead concentrations are higher in young children than in other age groups, whereas little is known regarding concentrations of other metals in young children. We measured the concentrations of a suite of metals in the blood of children 1-6 years of age, and assessed potential differences by age, season, or region of Maine. We used blood submitted to the Maine State Health and Environmental Testing Laboratory for blood lead analysis to determine the concentrations of arsenic (As), antimony (Sb), cadmium (Cd), manganese (Mn), mercury (Hg), selenium (Se), tin (Sn), and uranium (U) in 1350 children 1-6 years of age. The essential metals Mn and Se were detected in all samples, and As and Sb were detected in 490% of samples. Hg was detected in approximately 60% of samples. U and Cd were less often detected in blood samples, at approximately 30% and 10% of samples, respectively. Sn was not detected in any sample. Concentrations of As, Hg, and Se increased with age, whereas Sb decreased with age. Concentrations also varied by season and region for some though not all metals. Significant pairwise correlations were observed for a number of metals. Blood is a reasonable compartment for measurement of most of these metals in young children. The use of convenience samples provided a cost-effective mechanism for assessing exposure of young children in Maine.
“…However, the efficiency of biological utilization of selenium by a living organism appears to be related to the chemical form of selenium ingested (Lo and Sandi, 1980;Olson, 1986). With regards to humans, inorganic compounds seem to be less absorbed than selenomethionine, a selenium form which serves for selenium storage in proteins (Beilstein and Whanger, 1996;Dubois and Belleville, 1988).…”
Enantioseparation and determination of selenomethionine enantiomers in selenized yeast was investigated using chiral separation techniques based on different principles, coupled on-line to inductively coupled plasma mass spectrometry (ICP-MS) for selenium-specific detection. High performance liquid chromatography (HPLC) on a beta-cyclodestrin (beta-CD) column, cyclodextrin-modified micellar electrokinetic chromatography (CD-MEKC), gas chromatography (GC) on a Chirasil-L-Val column, and HPLC on a Chirobiotic T column have been investigated as the chiral separation techniques. For HPLC separation on the beta-CD column, and also for CD-MEKC, selenomethionine enantiomers were derivatized with NDA/CN(-). For chiral separation by GC, selenomethionine enantiomers were converted into their N-trifluoroacetyl (TFA)-O-alkyl esters. The developed hybridation methodologies are compared with respect to enantioselectivity, sensitivity and analysis time. The usefulness of the best-suited method [HPLC (Chirobiotic T)-ICP-MS] was demonstrated by its application to the successful chiral speciation of selenium and D-and L-selenomethionine content determination in selenized yeast.
“…The general feeling that methylation processes are a form of detoxification seems to hold for selenium because dimethylselenide has much lower acute toxicity (at least 200-fold) than do the inorganic selenium species selenite/ selenate and selenoamino acids (Table 1) (12 ). The rapid excretion of dimethylselenide, 71-79% by the rat in 6 h (10 ), is also suggestive of a metabolically inert detoxification product.…”
mentioning
confidence: 99%
“…The rapid excretion of dimethylselenide, 71-79% by the rat in 6 h (10 ), is also suggestive of a metabolically inert detoxification product. Surprisingly, TMSe is at least 20-fold more toxic than dimethylselenide (12 ), and thus the further methylation step to give TMSe does not appear to benefit the organism in terms of detoxification.…”
Background: Selenium is an essential trace element that also elicits toxic effects at modest intakes. Investigations of selenium metabolites in urine can help our understanding of the transformations taking place in the body that produce these beneficial and detrimental effects. There is, however, considerable discord in the scientific literature regarding the selenium metabolites thought to play important roles in these biotransformation processes. Approach: We critically assessed the published reports on selenium urinary metabolites, from the first report in 1969 to the present, in terms of the rigor of the data on which structures have been proposed. Content: We present and discuss data from ϳ60 publications reporting a total of 16 identified selenium metabolites in urine of humans or rats, a good model for human selenium metabolism. We assessed the analytical methods used and the validity of the ensuing structural assignments. Summary: Many of the studies of selenium metabolites in urine appear to have assigned incorrect structures to the compounds. The long-held view that trimethylselenonium ion is a major human urinary metabolite appears unjustified. On the other hand, recent work describing selenosugars as major urinary metabolites looks sound and provides a firm basis for future studies.
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