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 [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 language | English |
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Pages (from-to) | 321-325 |
Number of pages | 6 |
Journal | Biological Trace Element Research |
Volume | 34 |
Issue number | 3 |
Publication status | Published - Sept 1992 |
Keywords
- selenium deficiency
- thyroid hormones
- iodine deficiency
- effect of dietary selenium
- iodothyronine deiodinases
- the role of selenium
- iodothyronine deiodinase
- brown adipose-tissue
- rat-liver
- 5'-DEIODINASE
- inhibition
- protein
- 5'-deiodinase