title: The role of selenium in thyroid hormone metabolism and effects of selenium deficiency on thyroid hormone and iodine metabolism.
abstract: 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 [125I]N-bromoacetyl reverse triiodothyronine, is also labeled with 75Se by in vivo treatment of rats with 75Se-Na2SeO3. 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.
authors.affiliation: Division of Biochemical Sciences, Rowett Research Institute, Bucksburn, Aberdeen, UK.
authors.forename: J R
authors.initials: JR
authors.lastname: Arthur
authors.forename: F
authors.initials: F
authors.lastname: Nicol
authors.forename: G J
authors.initials: GJ
authors.lastname: Beckett
mesh_terms: D000818:Animals; D007453:Iodide Peroxidase / Q000097:blood; D007455:Iodine / Q000378:metabolism*; D051381:Rats; D012643:Selenium / Q000172:deficiency* / Q000502:physiology; D013963:Thyroid Hormones / Q000378:metabolism*; D013972:Thyrotropin / Q000378:metabolism; D013974:Thyroxine / Q000378:metabolism; D014284:Triiodothyronine / Q000378:metabolism
chemical_list: D013963:Thyroid Hormones; D014284:Triiodothyronine; D013972:Thyrotropin; D007455:Iodine; D007453:Iodide Peroxidase; D012643:Selenium; D013974:Thyroxine