Effect of cold exposure on thyroxine 5 prime -deiodinase activity in iron-deficient rats

Conference · Sun Mar 10 23:00:00 EST 1991 · FASEB Journal (Federation of American Societies for Experimental Biology); (United States)

OSTI ID:5375902

Brigham, D E; Beard, J L ^[1]

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1. Pennsylvania State Univ., University Park (United States)

When exposed to cold, severely anemic iron-deficient (ID) rats become hypothermic, fail to adequately increase metabolic rate, and have lower interscapular brown adipose tissue (IBAT) thyroxine 5{prime}-deiodinase (5{prime}-DI) activity compared to control (CN) rats. Less severely anemic rats and CN rats were exposed to 4C for 6h. Rectal temperatures were measured hourly, and VO{sub 2} was measured both prior to and throughout the cold exposure period. IBAT 5{prime}-DI activity was measured in cold-exposed ID and CN rats and compared to ID and CN rats that were not cold exposed. During cold exposure, both ID and CN rats increased metabolic rate similarly. IBAT 5{prime}-DI activity also increased similarly in both groups after cold exposure. These results show that moderately anemic DI rats acutely increase metabolic rate and IBAT 5{prime}-DI activity in the cold. This suggests brown fat production of thyroid hormone is not limiting thermoregulatory performance.

• OSTI ID: 5375902
• Report Number(s): CONF-9104107--
• Journal Information: FASEB Journal (Federation of American Societies for Experimental Biology); (United States), Journal Name: FASEB Journal (Federation of American Societies for Experimental Biology); (United States) Vol. 5:4; ISSN FAJOE; ISSN 0892-6638
• Country of Publication: United States
• Language: English

Related Subjects

560200* -- Thermal Effects
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ADIPOSE TISSUE
AMINO ACIDS
ANIMAL TISSUES
BIOLOGICAL EFFECTS
BODY
BODY TEMPERATURE
CARBOXYLIC ACIDS
CONNECTIVE TISSUE
ELEMENTS
ENZYME ACTIVITY
ENZYMES
HORMONES
HYPOTHERMIA
IRON
METABOLISM
METALS
NUTRITIONAL DEFICIENCY
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC IODINE COMPOUNDS
OXIDOREDUCTASES
PEPTIDE HORMONES
PEROXIDASES
PROTEINS
TEMPERATURE EFFECTS
THYROID HORMONES
THYROXINE
TISSUES
TRANSITION ELEMENTS