The role of selenium in thyroid-hormone metabolism and effects of selenium deficiency on thyroid-hormone and iodine-metabolism

John Arthur, Fergus Nicol, G J BECKETT

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Selenium deficiency impairs thyroid hormone metabolism by inhibiting the synthesis and activity of the iodothyronine deiodinases, which convert thyroxine (T4) to the more metabolically active 3,3'-5 triiodothyronine (T3). Hepatic type I iodothyronine deiodinase, identified in partially purified cell fractions using affinity labeling with [I-125]N-bromoacetyl reverse triiodothyronine, is also labeled with Se-75 by in vivo treatment of rats with (Se-Na2SeO3)-Se-75. Thus, the type I iodothyronine 5'-deiodinase is a selenoenzyme. In rats, concurrent selenium and iodine deficiency produces greater increases in thyroid weight and plasma thyrotrophin than iodine deficiency alone. These results indicate that a concurrent selenium deficiency could be a major determinant of the severity of iodine deficiency.

Original languageEnglish
Pages (from-to)321-325
Number of pages6
JournalBiological Trace Element Research
Issue number3
Publication statusPublished - Sep 1992


  • selenium deficiency
  • thyroid hormones
  • iodine deficiency
  • effect of dietary selenium
  • iodothyronine deiodinases
  • the role of selenium
  • iodothyronine deiodinase
  • brown adipose-tissue
  • rat-liver
  • inhibition
  • protein
  • 5'-deiodinase

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