Estrous cycle and cold stress 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:5375860

Smith, S M; Bucher, D R; Lukaski, H C ^[1]

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1. USDA/ARS, Grand Forks, ND (United States)

Female iron-deficient (ID) rats have plasma triiodothyronine (T{sub 3}) concentrations similar to iron sufficient controls (CN) at 24C. Whether the apparently euthyroid ID female can thermoregulate when exposed to cold was studied to assess the interactive effects of iron deficiency and the female reproductive cycle. Rats were assigned to either ID (n = 60) or CN (n = 60) diets for a period of five weeks. The two groups were then subdivided into five groups, four based on stage of the estrous cycle and the fifth group was ovariectomized one week prior to sacrifice. Animals were exposed to 4C for 6 h. Following sacrifice, tissues were collected for analysis of thyroid hormone and iron status indices. There was an interactive effect of iron status and the estrous cycle on core temperature response to the cold. Plasma thyrozine (T{sup 4}) concentrations were unaffected by iron status or the estrous cycle, and plasma T{sub 3} concentrations were significantly lower in ID than CN rats. Thyroxine 5{prime} - deiodinase activity in the liver was significantly lower in ID animals than CN; this conforms with the plasma T{sub 3} findings. Brown adipose tissue deiodinase was not affected by either iron status or the estrous cycle. In conclusion, iron deficiency impairs thermoregulation in rats, and this effect is related to the ovarian cycle. However, brown adipose tissue does not appear specifically involved in this defect.

• OSTI ID: 5375860
• 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 0892-6638; ISSN FAJOE
• 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
ANIMAL TISSUES
ANIMALS
BIOLOGICAL EFFECTS
BIOLOGICAL STRESS
BIOSYNTHESIS
BODY
BODY TEMPERATURE
CONNECTIVE TISSUE
DIGESTIVE SYSTEM
ELEMENTS
ENZYME ACTIVITY
ENZYMES
ESTROUS CYCLE
GLANDS
HORMONES
HYPOTHERMIA
IRON
LIVER
MAMMALS
METALS
NUTRITIONAL DEFICIENCY
ORGANIC COMPOUNDS
ORGANS
OXIDOREDUCTASES
PEPTIDE HORMONES
PEROXIDASES
PROTEINS
RATS
REPRODUCTION
RODENTS
SYNTHESIS
THYROID HORMONES
TISSUES
TRANSITION ELEMENTS
TRIIODOTHYRONINE
VERTEBRATES