Fluorometric Determination of Selenium in Biological Material with 2,3-Diaminonaphthalene.

Jh, Watkinson

doi:10.1021/ac60233a025

Cited by 631 publications

(168 citation statements)

References 16 publications

(18 reference statements)

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“…In addition, when used the isotonic phosphate buffer containing penicillamine instead of the plasma in the selenium export experiment, the selenium species exported was found in the chemical form of selenotrisulfide. 41 These results suggested a relay mechanism for the selenium transport from the N-CPD to the MSD in the AE1 protein.…”

Section: Discussionmentioning

confidence: 89%

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A thiol-mediated active membrane transport of selenium by erythroid anion exchanger 1 protein

et al. 2012

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In this paper, we describe a thiol-mediated and energy-dependent membrane transport of selenium by erythroid anion exchanger 1 (AE1, also known as band 3 protein). The AE1 is the most abundant integral protein of red cell membranes and plays a critical role in the carbon dioxide transport system in which carbon dioxide is carried as bicarbonate in the plasma. This protein mediates the membrane transport of selenium, an essential antioxidant micronutrient, from red cells to the plasma in a manner that is distinct from the already known anion exchange mechanism. In this pathway, selenium bound to the cysteine 93 of the hemoglobin β chain (Hb-Cysβ93) is transported by the relay mechanism to the Cys317 of the amino-terminal cytoplasmic domain of the AE1 on the basis of the intrinsic interaction between the two proteins and is subsequently exported to the plasma via the Cys843 of the membrane-spanning domain. The selenium export did not occur in plain isotonic buffer solutions and required thiols, such as albumin, in the outer medium. Such a membrane transport mechanism would also participate in the export pathways of the nitric oxide vasodilator activity and other thiol-reactive substances bound to the Hb-Cysβ93 from red cells to the plasma and/or peripherals. 2 IntroductionSelenium belongs to chalcogens that shares similar chemical properties especially with sulfur and, to a lesser extent, with tellurium. This element is an essential micronutrient for humans and other higher animal species. 1 Selenocysteine (SeCys), the 21st naturally occurring amino acid encoded by the UGA codon, is the form of selenium present in enzymes and proteins. In humans, 25 SeCys-containing proteins (selenoproteins) are identified on the basis of their selenoproteome analysis. 2 The best-known selenoproteins are the glutathione peroxidases (GPxs) that can catalyze the reduction of certain peroxide species (R−OOH) to the alcohols (R−OH) at their active center SeCys residue. 1,3 Nutritional selenium is thought to be obtained from a variety of selenium compounds in the diet, mostly in organic forms, such as SeCys and selenomethionine (SeMet). During the systemic delivery of selenium, selenoprotein P that is present in the plasma is thought to be the selenium supply protein for the biosynthesis of the other selenoproteins including GPxs. 4,5 Recent evidence in selenoprotein P (SelP) knockout mice has shown that the distribution of selenium from the liver to testis and brain is mediated by Sel P. 6,7 It is also found that in the absence of SelP, selenium from selenious acid (SA, H 2 SeO 3 ) in the diet can be distributed to the peripherals by a yet unknown mechanism. 8 So far, little is known about the membrane transport of selenium from selenium source compounds, including SA. Inorganic SA is rare as a chemical form of the food source compounds, but highly bioavailable SA is most frequently used as a source compound for the treatment of a selenium deficiency. 9Selenium-enriched yeast (a common form of selenium supplement) is found to contain ...

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Section: Discussionmentioning

confidence: 89%

“…41 The selenium standard solution [1000 ppm as selenium (IV) dioxide in 0.5 M nitric acid] for the fluorometry was obtained from Kanto Chemical Co., Inc.…”

Section: Determination Of Membrane Protein and Selenium Concentrationsmentioning

confidence: 99%

A thiol-mediated active membrane transport of selenium by erythroid anion exchanger 1 protein

et al. 2012

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“…Cord-blood THg was used for the data analysis and maternal-hair THg was for a comparable index of prenatal methylmercury exposure. Cord plasma selenium concentrations were determined fluorometrically after ashing the plasma samples with a mixture of nitrate and perchloric acid (Watkinson 1966). Accuracy was ensured using a certified reference material (Seronorm Trace Elements Serum L-1, Lot 0903106, Sero, Norway) for quality control.…”

Section: Exposure Biomakersmentioning

confidence: 99%

Psychomotor Ability in Children Prenatally Exposed to Methylmercury: The 18-Month Follow-Up of Tohoku Study of Child Development

Tatsuta

Murata

Iwai-Shimada

et al. 2017

Tohoku J. Exp. Med.

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Fish contain nutrients essential to the developing fetal brain, but they are contaminated with methylmercury. The Tohoku Study of Child Development, now underway in the Sanriku coastal area of Miyagi prefecture, Japan, follows mother-child pairs to examine the risks and benefits of fish consumption during pregnancy, especially the effects of prenatal exposures to methylmercury, selenium, and docosahexaenoic acid (DHA) on child neurodevelopment. Children aged 18 months were administered the Bayley Scales of Infant Development second edition (BSID-II) and Kyoto Scale of Psychological Development (KSPD) in [2004][2005][2006][2007][2008]. Complete data of cord-blood total mercury (THg), cord-plasma selenium, maternal-plasma DHA, the above test scores, and confounders for 566 mother-child pairs were available. The median cord-blood THg level was 15.7 (range, 2.7-96.1) ng/g. Since the BSID-II and KSPD scores were significantly lower in the 285 boys than in the 281 girls, analyses were conducted separately. The Psychomotor Development Index (PDI) of BSID-II was significantly correlated with cord-blood THg only in the boys, and significance of the association remained unchanged after adjusting for possible confounders; i.e., a 10-fold increase in cordblood THg was associated with a 8.3-point decrease in the score of the PDI. Other significant correlations of THg were not seen in the boys or girls. Selenium and DHA showed no significant correlations with the BSID-II or KSPD scores in either sex. In conclusion, intrauterine methylmercury exposure may affect psychomotor development, and boys appear to be more vulnerable to the exposure than girls.

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“…The value of hematocrit was obtained after centrifugation at 11,000 rpm for 5 min with a Hematocrit Centrifuge (Kubota Model KH-120, Tokyo). Selenium was analyzed by the method of Watkinson (1966). Mercury was measured by the method of Yamamoto et al (1980), which enables the mercury measurement under coexistence of selenium.…”

Section: Methodsmentioning

confidence: 99%

Decreased membrane fragility of mouse erythrocytes by small dose of methylmercury and its restoration by coadministered selenite.

Yamamoto

Suzuki

1982

Tohoku J. Exp. Med.

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Med., 1982, 137 (3), [297][298][299][300][301][302][303] Female IVCS mice were fed methylmercury at a low dose level (10 nmoles/g feed) with coadministration of selenite (0, 8,20 or 50 nmoles/ml of drinking water) for one week or two weeks. Mice fed methylmercury alone showed the decreased fragility of erythrocytes membrane when compared with the non-treated control. Coadministration of selenite produced such a change to smaller extents than methylmercury treatment alone. Mercury levels in the blood varied according to the dose level of selenite (the highest level was found in methylmercury alone group). -membrane fragility; blood; mouse; methylmercury; selenite In the in vitro experiments, hemolysis was observed at concentrations of methylmercury over 10-4 M in rat erythrocytes (Ohmiya 1977;Tanaka and Nakai 1977). Elevated fragility of erythrocytes was observed in rats injected subcutaneously for 12 days with daily dose of 10 mg methylmercury chloride/kg (Okuda and Tsuzuki 1977). Coadministration of selenite with methylmercury produced changes in mercury retention in the blood of mice and rats (Iwata et al. 1973;Stillings et al. 1974; Ohi et al. 1975;Yamane et al. 1977;Sumino et al. 1977; Magos and Webb 1977;Satoh and Suzuki 1979;Naganuma and Imura 1980), but has not been studied for hemolytic effects. The change of mercury retention in the blood by coadministered selenium was not always unidirectional by dose levels and dose combination of both chemicals, duration of dosing and animal species.In this study, to elucidate subtle effects of methylmercury on erythrocytes, a low dose level was selected with varying coadministered dose of selenite. MATERIALS AND METHODSForty-four female IVCS mice, 17 weeks-old weighing 27 to 30 g, were divided into nine groups and fed methylmercury (10 nmoles/g feed) and selenite (0, 8,20 or 50 nmoles/ml of drinking water) for one week or two weeks. The control (commercial chow and tap water only) was bred only for one week.

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Fluorometric Determination of Selenium in Biological Material with 2,3-Diaminonaphthalene.

Cited by 631 publications

References 16 publications

A thiol-mediated active membrane transport of selenium by erythroid anion exchanger 1 protein

A thiol-mediated active membrane transport of selenium by erythroid anion exchanger 1 protein

Psychomotor Ability in Children Prenatally Exposed to Methylmercury: The 18-Month Follow-Up of Tohoku Study of Child Development

Decreased membrane fragility of mouse erythrocytes by small dose of methylmercury and its restoration by coadministered selenite.

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