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The underlying mechanisms by which estrogen regulates energy metabolism and body composition
Author(s) -
Ezzat-Zadeh Zahra,
Dodge Bonnie G,
Elam Marcus,
Feresin Rafaela,
Browne Jenna,
Kim Jeong-Su,
Arjmandi Bahram H
Publication year - 2012
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.26.1_supplement.564.8
Subject(s) - ovariectomized rat , medicine , endocrinology , anabolism , bone mineral , lean body mass , estrogen , bone remodeling , chemistry , osteoporosis , body weight
Ovariectomized rats gain excess body weight (BW) even when they are pair‐fed to sham animals. This higher BW, contrary to common belief, does not result in higher bone mineral density (BMD). The purpose of the present study is to evaluate the potential mechanisms underlying these paradoxical observations. Eighteen 10‐mo old female Sprague‐Dawley rats (n=6/group) were divided into either a sham‐operated group (sham) or two ovariectomized groups receiving 17β‐estradiol at the dose of 10μ/kg BW (ovx+E 2 ) or solvent vehicle (ovx) twice per week. At the present time (100 days post‐surgery), animals have been scanned using DXA for total BMD, fat mass (FM) and lean mass. Currently, the mean BW of the ovx group without E 2 is significantly higher than the animals in the sham and ovx+E 2 groups (sham: 396.80 ± 13.51 vs. ovx: 437.83 ± 13.25 g). This significant increase in BW is related to a significant increase in mean total FM (sham: 211.0 ± 11.57 vs. ovx: 248.66 ± 11.20 g). DXA scans indicated a trend in BMD loss in the ovx control group ( P =0.9). Animals will be sacrificed once the loss of mean total BMD in ovx rats reaches a significant level ( P <0.05). This study intends to investigate the mechanisms by which ovarian hormone deficiency alters energy metabolism by assessing anabolic and catabolic factors as well as oxidative and inflammatory loads in selected tissues such as muscle and bone.