| Title | Thyroxine 5'-deiodination in brown adipose tissue and pineal gland: implications for thermogenic regulation and role of melatonin. | | Author(s) | Puig-Domingo M, Guerrero JM, Reiter RJ, Tannenbaum MJ, Hurlbut EC, Gonzalez-Brito A, Santana C | | Institution | Department of Cellular and Structural Biology, University of Texas Health Science Center, San Antonio 78284. | | Source | Endocrinology 1988 Aug; 123(2):677-80. | | MeSH | Adipose Tissue, Brown
Animals
Body Temperature Regulation
Cerebellum
Cerebral Cortex
Cold
Female
Iodide Peroxidase
Iodine Radioisotopes
Male
Median Eminence
Melatonin
Methimazole
Pineal Gland
Sciuridae
Thyroxine
| | Abstract | T4 type II 5'-deiodinase (5'-D II) activity was studied in wild-captured Richardson's ground squirrels. As previously reported for other species, 5'-D II activity was detected in frontal cortex, cerebellum, pineal gland, and brown adipose tissue (BAT); in the median eminence the levels of 5'-D II activity were undetectable with our methodology. When pineal gland, frontal cortex, and cerebellum nyctohemeral profiles were studied, none of them showed variations. Cold exposure for 4 h led to an increase in the enzymatic activity 10-fold above the basal values for BAT, while in the pineal gland the values were doubled; cold exposure failed to change the 5'-D II activity in the frontal cortex. Acute melatonin treatment caused a 7-fold increase in 5'-D II activity in BAT, but did not affect enzyme activity in either the pineal gland or frontal cortex. The data indicate that 5'-D II in Richardson's ground squirrel shows classical localizations. Additionally, two new regulatory factors of 5'-D II are reported, i.e. melatonin for BAT and cold for the pineal gland. | | Language | eng | | Pub Type(s) | Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.
| | PubMed ID | 3396504 |
|
