title: Female mice and rats exhibit species-specific metabolic and behavioral responses to ovariectomy.
abstract: Ovariectomy (OVX) leads to hyperphagia and weight gain in rats, which can be prevented by estradiol (E2) replacement; however, the role of endogenous E2 on feeding and energy homeostasis in female mice has not been well characterized. The primary goal of this study was to assess the relative contribution of increased energy intake and decreased energy expenditure to OVX-induced weight gain in female rats and mice. OVX led to hyperphagia in rats, but did not produce daily, nor cumulative, hyperphagia in mice. OVX decreased mass-specific metabolic rate in mice, but not in rats. OVX decreased home cage locomotor activity in both species. Pair-feeding attenuated OVX-induced weight gain in rats and produced both short- and long-term changes in expression of key hypothalamic genes involved in food intake and energy homeostasis, i.e., the anorexigenic neuropeptide pro-opiomelanocortin (POMC) and the orexigenic neuropeptides: melanin-concentrating hormone (MCH) and agouti-related peptide (AgRP). No differences in hypothalamic gene expression were observed between OVX'd and sham mice. The results suggest that OVX-induced weight gain is mediated by hyperphagia and reduced locomotor activity in rats, but that in mice, it is primarily mediated by reduced locomotor activity and metabolic rate.
authors.affiliation: Department of Biomedical Sciences and The Program in Neuroscience, Florida State University, Tallahassee, FL 32306-4300, USA.
authors.forename: Michelina Messina
authors.initials: MM
authors.lastname: Witte
authors.forename: David
authors.initials: D
authors.lastname: Resuehr
authors.forename: Ashley R
authors.initials: AR
authors.lastname: Chandler
authors.forename: Ashlee K
authors.initials: AK
authors.lastname: Mehle
authors.forename: J Michael
authors.initials: JM
authors.lastname: Overton
mesh_terms: D000818:Animals; D002153:Calorimetry, Indirect; D004435:Eating / Q000502:physiology; D004734:Energy Metabolism / Q000502:physiology; D005260:Female; D051379:Mice; D008810:Mice, Inbred C57BL; D009043:Motor Activity / Q000502:physiology; D009479:Neuropeptides / Q000378:metabolism; D010052:Ovariectomy / Q000009:adverse effects*; D011333:Pro-Opiomelanocortin; D051381:Rats; D020318:Rats, Long-Evans; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015430:Weight Gain / Q000502:physiology
chemical_list: D009479:Neuropeptides; D011333:Pro-Opiomelanocortin