Inactivation of brown adipose tissue thermogenesis by oestradiol treatment in cold-acclimated rats
Puerta, M.L.; Nava, M.P.; Abelenda, M.; Fernández, A.
Pflugers Archiv European Journal of Physiology 416(6): 659-662
1990
ISSN/ISBN: 0031-6768 PMID: 2247337 Document Number: 350622
Both cold-acclimated female rats and rats at thermoneutrality received 0.15-0.20 mg daily of 17 .beta.-oestradiol over 15 days via a Silastic capsule implanted subcutaneously. Controls received empty implants. Comparison between the oestradiol-treated animals and the untreated controls revealed that at thermoneutrality, oestradiol treated decreased food intake and body weight gain, but did not affect brown adipose tissue (BAT) thermogenesis and composition. By contrast, in cold-acclimated rats, oestradiol treatment did not modify food intake or body weight gain, but it decreased BAT thermogenesis. It is concluded that the effects of oestradiol treatment on BAT depend on the activity of the tissue, i.e. it has no effect on BAT when the tissue is thermogenically inactive, but it decreases cold-induced BAT thermogenesis. It is suggested that oestradiol could be the hormonal factor responsible for the previously observed inactivation of BAT thermogenesis during pregnancy in cold-acclimated rats.