Abstract
The activity of the type II iodothyronine 5'-deiodinase enzyme in brown adipose tissue has been examined in rats fed a selenium-deficient diet. Iodothyronine 5'-deiodinase activity was threefold lower in brown adipose tissue of deficient rats than in control animals. The activity of glutathione peroxidase, a biochemical index of selenium deficiency, was also greatly decreased in deficient animals. Cytochrome oxidase activity in brown fat was, however, unaltered by selenium deficiency. Acute exposure to cold (4-degrees-C for 18 h) resulted in a substantial increase in iodothyronine 5'-deiodinase activity in brown adipose tissue of control rats, but the stimulatory effect of cold was attenuated in selenium-deficient animals. These results support the concept that the iodothyronine 5'-deiodinases are selenium-dependent enzymes, and indicate that the thermogenic response to cold may be impaired in selenium deficiency.
Original language | English |
---|---|
Pages (from-to) | 782-785 |
Number of pages | 4 |
Journal | Canadian Journal of Physiology and Pharmacology |
Volume | 69 |
Issue number | 6 |
Publication status | Published - Jun 1991 |
Keywords
- IODOTHYRONINE 5'-DEIODINASE
- GLUTATHIONE PEROXIDASE
- SELENIUM DEFICIENCY
- BROWN ADIPOSE TISSUE
- COLD EXPOSURE
- UNCOUPLING PROTEIN
- RAT-LIVER
- TRIIODOTHYRONINE
- THYROXINE
- INHIBITION
- NOREPINEPHRINE