101. Estrogen modulates central and peripheral responses to cold in female rats
- Author
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Ken Tokizawa, Kei Nagashima, Yuki Uchida, Saki Yasuhara, Akiko Kobayashi, and Masumi Kano
- Subjects
Cell physiology ,endocrine system ,medicine.medical_specialty ,Physiology ,medicine.drug_class ,Acclimatization ,Ovariectomy ,Hypothalamus ,Adipose tissue ,Biology ,Internal medicine ,medicine ,Animals ,Rats, Wistar ,Dorsomedial hypothalamic nucleus ,Estrous cycle ,Estrogens ,Thermoregulation ,Thermogenin ,Rats ,Cold Temperature ,Endocrinology ,Adipose Tissue ,Estrogen ,Female ,Heat-Shock Response ,hormones, hormone substitutes, and hormone antagonists ,Body Temperature Regulation - Abstract
The aim of this study was to determine whether estrogen modulates central and peripheral responses to cold in female rats. In ovariectomized female rats with and without administered estrogen [E(2) (+) and E(2) (-), respectively], the counts of cFos-immunoreactive cells in the medial preoptic nucleus (MPO) and dorsomedial hypothalamic nucleus (DMH) in the hypothalamus were greater in the E(2) (+) rats than in the E(2) (-) rats at 5 degrees C. Examination of the response of normal female rats to exposure to 5 degrees C at different phases of the estrus cycle revealed that counts of cFos-immunoreactive cells in the MPO, DMH, and posterior hypothalamus and the level of uncoupling protein 1 mRNA in the brown adipose tissues were greater in the proestrus phase than on day 1 of the diestrus phase. This result was linked to the level of plasma estrogen. The body temperature during cold exposure was higher in the E(2) (+) rats than in the E(2) (-) rats and was also higher in the proestrus phase than on day 1 of the diestrus phase. We conclude that estrogen may affect central and peripheral responses involved in thermoregulation in the cold.
- Published
- 2009
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