Selenium and the thyroid

Köhrle, Josef

doi:10.1097/01.med.0000433066.24541.88

Cited by 84 publications

(69 citation statements)

References 69 publications

(74 reference statements)

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“…For instance, levels of liver GPX1 mRNA and activity in selenium-adequate pregnant rats declined to ;50% of levels in nonpregnant rats, illustrating the need to fully characterize biomarker expression at all stages of the life cycle (18). Similarly, thyroxine deiodinase activity is also regulated by iodine status (via thyroid stimulating factor), at least in thyroid (45), complicating the use of thyroxine deiodinase as a robust selenium biomarker.…”

Section: Discussionmentioning

confidence: 99%

Insights for Setting of Nutrient Requirements, Gleaned by Comparison of Selenium Status Biomarkers in Turkeys and Chickens versus Rats, Mice, and Lambs

Sunde

Taylor

2016

Advances in Nutrition

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To gain insights into nutrient biomarkers and setting of dietary nutrient requirements, selenium biomarker levels and requirements in response to multiple graded levels of dietary selenium were compared between day-old turkeys and chickens versus weanling rats and mice and 2-d-old lambs supplemented with sodium selenite. In rodents, there was no significant effect of dietary selenium on growth, indicating that the minimum selenium requirement was <0.007 mg Se/g diet. In contrast, there was a significant effect in turkeys, chicks, and lambs, which showed selenium requirements for growth of 0.05, 0.025, and 0.05 mg Se/g diet, respectively. Liver glutathione peroxidase (GPX) 1 activity fell in all species to <4% of selenium-adequate levels, plasma GPX3 activity fell to <3% in all species except for mice, and liver GPX4 activity fell to <10% in avians but only to ;50% of selenium-adequate levels in rodents. Selenium-response curves for these biomarkers reached well-defined plateaus with increasing selenium supplementation in all species, collectively indicating minimum selenium requirements of 0.06-0.10 mg Se/g for rats, mice, and lambs but 0.10-0.13 mg Se/g for chicks and 0.23-0.33 mg Se/g for turkeys. In contrast, increasing dietary selenium did not result in well-defined plateaus for erythrocyte GPX1 activity and liver selenium in most species. Selenium-response curves for GPX1 mRNA for rodents and avians had well-defined plateaus and similar breakpoints. GPX4 mRNA was not significantly regulated by dietary selenium in rodents, but GPX4 mRNA in avians decreased in selenium deficiency to ;35% of selenium-adequate plateau levels. Notably, no selenoprotein activities or mRNA were effective biomarkers for supernutritional selenium status. Robust biomarkers, such as liver GPX1 and plasma GPX3 activity for selenium, should be specific for the nutrient, fall dramatically in deficiency, and reach well-defined plateaus. Differences in biomarker-response curves may help researchers better understand nutrient metabolism and targeting of tissues in deficiency, thus to better characterize requirements. Adv Nutr 2016;7:1129-38.

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Section: Discussionmentioning

confidence: 99%

Insights for Setting of Nutrient Requirements, Gleaned by Comparison of Selenium Status Biomarkers in Turkeys and Chickens versus Rats, Mice, and Lambs

Sunde

Taylor

2016

Advances in Nutrition

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“…SeMet possesses excellent bioavailability and lower toxicity, and therefore it is more applicable for long-term administration. 10 Recently, the introduction of nanosize elemental selenium produced a highly effective molecular compound, and when compared with SeMet, it showed similar efficacy in increasing antioxidant GPx activity while displaying lower toxicity.…”

Section: Introductionmentioning

confidence: 99%

The prospective protective effect of selenium nanoparticles against chromium-induced oxidative and cellular damage in rat thyroid

Hassanin¹,

El-Kawi²,

Hashem³

2013

IJN

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Background: Nanotechnology has enabled researchers to synthesize nanosize particles that possess increased surface areas. Compared to conventional microparticles, it has resulted in increased interactions with biological targets. Objective: The objective of this study was to determine the protective ability of selenium nanoparticles against hexavalent chromium-induced thyrotoxicity. Design: Twenty male rats were used in the study, and arbitrarily assigned to four groups. Group 1 was the control group, and was given phosphate-buffered saline. Group 2 was the chromium-treated group and was given K 2 Cr 2 O 7 60 µg/kg body weight intraperitoneally as a single dose on the third day of administration. Group 3 was the nano-selenium-treated group and was given selenium nanoparticles (size 3-20 nm) 0.5 mg/kg body weight intraperitoneally daily for 5 consecutive days. Group 4 was the nano-selenium chromium-treated group, which received selenium nanoparticles for 5 days and a single dose of K 2 Cr 2 O 7 on the third day of administration. Materials and methods: Blood samples were collected from rats for measuring thyroid hormones (free triiodothyronine [T 3 ] and free thyroxine [T 4 ]) and oxidative and antioxidant parameters (malondialdehyde [MDA], reduced glutathione [GSH], catalase, and superoxide dismutase [SOD]). Upon dissection, thyroid glands were taken for histopathological examination by using paraffin preparations stained with hematoxylin and eosin (H&E) and Masson's trichrome. Immunohistochemical staining was performed for detecting cellular proliferation using Ki67 antibodies.Results: The present study shows that K 2 Cr 2 O 7 has a toxic effect on the thyroid gland as a result of inducing a marked oxidative damage and release of reactive oxygen species. This was shown by the significant decrease in free T 3 and T 4 and GSH levels, which was accompanied by significant increases in catalase, SOD, and MDA in the chromium-treated group compared to the control group. Se nanoparticles have a protective effect on K 2 Cr 2 O 7 -induced thyroid damage, as a result of correcting the free T 3 and T 4 levels and GSH, catalase, SOD, and MDA compared to the K 2 Cr 2 O 7 -treated group. Administration of nano-selenium alone in the nano-selenium-treated group had no toxic effect on rats' thyroid compared to the control group. The biochemical results were confirmed by histopathological, immunohistochemical and pathomorphological studies.

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“…Previous studies have shown that selenium is indirectly involved in growth hormone secretion, as selenium is an important constituent of the deiodinase enzyme, which is necessary for the proper functioning of the thyroid hormones and takes part in the conversion of T 4 to T 3 , the biologically more active form of thyroid hormone (Kohrle and Gartner, 2009). In consequence, thyroid hormones (T 3 and T 4 ) are required for the proper secretion of growth hormone from the pituitary gland in all vertebrates including fish (Valcavi et al, 1992;Muller et al, 1999); thus, selenium is indirectly involved in growth hormone secretion.…”

Section: Introductionmentioning

confidence: 99%

Effects of dietary selenium nanoparticles on physiological andbiochemical aspects of juvenile Tor putitora

Khan¹,

Zuberi²,

Nazir³

et al. 2016

Turk J Zool

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A 70-day feeding trial was conducted to evaluate the effects of dietary supplementation of selenium nanoparticles (Se-NPs) on physiological and biochemical aspects of juvenile mahseer (Tor putitora) fish. Maintaining a 40% protein level, 2 different experimental diets supplemented with 0% Se-NPs and 0.68 Se-NPs mg kg -1 were fed to triplicate groups of fish. The experiment was conducted in a semistatic condition consisting of 6 fiber tanks. The fish were first acclimatized, and then 30 fish per tank were randomly put into each fiber tank. At the end of the feeding trial, samples were collected from the fish and analyzed. Results obtained showed that the diet supplemented with Se-NPs significantly increased (P < 0.05) physiological aspects like red blood cell count, hemoglobin level, hematocrit values, and lysozyme activity as compared to the basal diet. Similarly, biochemical parameters including serum growth hormone levels, tissue total protein content, and glutathione peroxidase activity in liver and muscle tissues of T. putitora also significantly (P < 0.05) increased. Thus, dietary Se-NP supplementation at the rate of 0.68 mg kg -1 diet has very beneficial effects on the physiobiochemical health aspects of juvenile T. putitora.

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Selenium and the thyroid

Abstract: Adequate nutritional supply of selenium, together with the two other essential trace elements iodine and iron, is required for a healthy thyroid during development and adolescence, as well as in the adult and aging populations.

Cited by 84 publications

References 69 publications

Insights for Setting of Nutrient Requirements, Gleaned by Comparison of Selenium Status Biomarkers in Turkeys and Chickens versus Rats, Mice, and Lambs

Insights for Setting of Nutrient Requirements, Gleaned by Comparison of Selenium Status Biomarkers in Turkeys and Chickens versus Rats, Mice, and Lambs

The prospective protective effect of selenium nanoparticles against chromium-induced oxidative and cellular damage in rat thyroid

Effects of dietary selenium nanoparticles on physiological andbiochemical aspects of juvenile Tor putitora

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