Plasma selenoprotein

Plasma selenoprotein - selenium mobilization to tissues and organs 134, 151-153... 

Plasma selenoprotein P, plasma GSPHx-3, and total plasma selenium concentration are aU lowered by the APR to injury or infection. This effect should be considered when interpreting plasma selenium values in postoperative patients or those with infection or inflammatory disease. 

Selenoprotein P Accounts for 60-80% of plasma selenoproteins contains up to 10 selenocysteines per molecule has a transport function binds mercury may protect the cardiovascular system and endothelial cells... 

The interaction between Ag+ and selenium in the bloodstream has been studied in vitro by means of the HPLC-inductively coupled argon plasma-mass spectrometry (ICPMS) method. The metal ions and selenide form the unit complex (AgSe) and then this unit binds to selenoprotein to form the ternary complex [(AgSe)ra] selenoprotein in the bloodstream.1042... 

Plasma (PGpx) - second most abundant selenoprotein in plasma, role 134, 135... 

B. Akesson, T. Bellew, R. Burk, Purification of selenoprotein P from human plasma, Biochim. Biophys. Acta, 1204 (1994), 243-249. 

Actually, glutathione peroxidase protects fromperoxynitrite-mediated oxidation and nitration reactions in model systems. Selenoprotein P from human plasma exhibits a similar property (A16, A17). A similar function of peroxynitritase has been ascribed to bacterial catalase/peroxidase (W10). 

A17. Arteel, G. E., Mostert, V., Oubrahim, H., Briviba, K., Abel, J., and Sies, H., Protection by selenoprotein P in human plasma against peroxynitrite-mediated oxidation and nitration. Biol. Chem. 379, 1201-1205 (1998). 

Plasma from mammalia contains a selenoprotein that carries more than 50% of the selenium present. In rat, about 8% of the total selenium content is associated with this protein, selenoprotein P. A change in the selenium status of the rat leads to a rapid change of the selenium level attached to selenoprotein P, preferential to changes of other selenoproteins such as plasma glutathione peroxidase. ... 

Selenium has functions in many selenoproteins and also in relation to the immune response. There is an association between low plasma selenium concentrations and oral cancer (1). Selenium compounds inhibit tumorigenesis in a variety of animal models, and added selenium in human diets might reduce the risk of cancer (SEDA-21, 240). 

The most commonly submitted samples for direct trace element analysis are of whole blood, blood plasma, or serum. Plasma protein levels of the relevant carrier proteins transferrin (Fe), albumin (Zn), ceruloplasmin (Cu), and selenoprotein P (Se) can give useful additional information. 

The concentrations of selenium in whole blood and in plasma and/or serum are related to dietary intake. About 50% to 60% of the total plasma selenium is present as the protein selenoprotein P, a highly basic protein having multiple histidine residues and about 10 atoms of selenium per molecule, Around 30% of plasma selenium is present as glutathione peroxidase (GSHPx-3) and the remainder is incorporated into albumin as selenomethionine. ... 

Selenoprotein P. This protein is the major selenium-containing protein in blood plasma, may be a transport protein for the element, and has an antioxidant function. ... 

Early animal studies and human population surveys used whole blood as the main indicator of selenium status. Whole blood selenium can be determined after acid digestion using a fluorometric method. The more convenient carbon furnace atomic absorption spectroscopy (CFAAS) assay for plasma and/or serum selenium is now the most widely used procedure. The main components of plasma selenium are extracellular glutathione peroxidase (GSHPx 3) and selenoprotein P. 

The major selenium-containing plasma protein selenoprotein P can be determined by immunological methods. The production of monoclonal antibodies to selenoprotein P has been described and used to study tlie structure and function of the protein and to quantify it. It is also possible to separate selenoprotein P from other plasma proteins by heparin affinity chromatography followed by CFAAS selenium analysis. Selenoprotein P concentration in plasma responds rapidly to supplementation and has been used in nutritional studies of Chinese populations to confirm the adequacy of intake. "... 

HiH KE, Xia Y, Akesson B, Boeglin ME, Burk RF. Selenoprotein P concentration in plasma is an index of selenium status in selenium-deficient and selenium-supplemented Chinese subjects. J Nutr 1996 126 138-45. 

Nichol C, Herdman J, Sattar N, O Dwyer PJ, St JO, Littlejohn D, Fed G. Changes in the concentrations of plasma selenium and selenoproteins after minor elective surgery further evidence for a negative acute phase response Clin Chem 1998 44 1764-6. 

Metabolic, nutritional and toxicological aspects of 160-163 Se were studied. The transport of Se within the organism and the urine metabolites observed were different, depending on the form of Se administred. Rapid and efficient incorporation of Se into SeP in the liver and excretion into the plasma followed by the slow and steady incorporation of Se into GPx in the kidneys and excretion into the plasma described. The formation of Se-methyl-/V-acetylselenohexosa-mine in liver and its excretion via urine were reported. The mechanisms underlying the interaction between Se and mercuric ions in the bloodstream were explained by the formation of a ternary complex, [(HgSe) ], -selenoprotein P... 

As a component of glutathione peroxidase and the iodothyronine 5 -deiodinases, selenium is an essential micronutrient for humans. Its role in the deiodinase enzymes may be one reason that children require more selenium for growth than adults. Selenium is also a component of the enzyme thioredoxin reductase, which catalyses the NADPH-dependent reduction of the redox protein thioredoxin. Other selenium-containing proteins of unknown functions, including selenoprotein P found in the plasma, have also been identified. Excess selenium administered as selenite and selenate has been shown to be metabolized to methylated compounds and excreted. 

Selenoprotein P which contains 10 selenocysteines, is the principal selenoprotein found in plasma (Sunde 1990). Selenoprotein P in plasma also does not continue to increase with increasing selenium and has been suggested as an alternative to GSH-Px as a biomarker for selenium status (Duffield et al. 1999 Huang et al. 1995). The function of selenoprotein P has still not been determined. 

Exposure. Selenium exposure can be correlated with concentrations detected in human blood, blood components, urine, hair, and nails. Selenium concentrations found in these biomarkers in the general population can be found in Table 3-7. However, these markers vary greatly among different populations (Longnecker et al. 1991). Levels of plasma, erythrocyte and platelet GSH-Px activity, as well as selenoprotein P may serve as better markers of selenium deficiency than selenium concentrations. 

Deagen JT, Butler JA, Zachara BA, et al. 1993. Determination of the distribution of selenium between glutathione peroxidase, selenoprotein P, and albumin in plasma. Anal Biochem 208(1) 176-181. 

Hagmar L, Persson-Moschos M, Akesson B, et al. 1998. Plasma levels of selenium, selenoprotein P and glutathione peroxidase and their correlations to fish intake and serum levels of thyrotropin and thyroid hormones A study on Latvian fish consumers. Eur J Clin Nutr 52 796-800. 

Huang W, Akesson B, Svensson BG. 1995. Selenoprotein P and glutathione peroxidase (EC 1.11.1.9) in plasma as indices of selenium status in relation to the intake of fish. Br J Nutr 73 455-461. 

Soderberg A, Sahaf B, Rosen A. 2000. Thioredoxin reductase, a redox-active selenoprotein, is secreted by normal and neoplastic cells Presence in human plasma. Cancer Res 60 2281-2289. 

Selenoprotein P Found in plasma and assooiated with the endothelial oell. Appears to protect endothelial cells against damage from peroxynitrite... 

Bendahl, L., Sidenius, U., and Gammelgaard, B. (2000). Determination of selenoprotein P in human plasma by solid phase extraction and inductively coupled plasma mass spectrometry.Chim.Acta 411(1), 103. 

The precise functional roles of selenoproteins P and W are not well understood. Selenoprotein P contains more selenium (up to 10 atoms per molecule) than any other mammalian selenoprotein, and it can form equimolar selenium-mercury complexes, thereby probably helping to detoxify mercury. It is the major selenoprotein fovmd in plasma and may also act as a selenium transport protein and selenium reserve. Selenoprotein W is found in muscle, and its decline may help explain the molecular basis of white muscle disease in selenium-deficient sheep. 

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