title: Retroperitoneal white adipose tissue mitochondrial function and adiponectin expression in response to ovariectomy and 17β-estradiol replacement.
abstract: Sexual dimorphism has been previously found both in mitochondrial biogenesis and function and in adiponectin expression of retroperitoneal WAT. However, little is known about the E2 effects on WAT mitochondrial function. Accordingly, the aim of this study was to examine in greater depth the role of estrogens in sexual dimorphism. This was accomplished by studying the effects of ovariectomy and E2 replacement on retroperitoneal WAT mitochondrial function. Fourteen-week-old female and ovariectomized (OVX) female Wistar rats were used in this study. The ovariectomy was performed at 5 weeks of age and at 10 weeks of age OVX rats were divided into two experimental groups: OVX, and OVX treated with 17β-estradiol (E2) (OVX+E2). Subcutaneous injections of E2 (10 μg/kg/48 h) were administered to the OVX+E2 rats for 4 weeks previous to the sacrifice whereas OVX rats were treated only with the vehicle. Levels of the main markers for mitochondrial biogenesis and function and those representatives of the antioxidant defense system and insulin sensitivity were determined. Additionally, the mRNA levels of the α and β estrogen receptors and of some adipocyte differentiation markers were studied. Our results indicate that retroperitoneal WAT was able to adapt itself to ovariectomy without any changes in mitochondrial function markers or for the adiponectin levels. However, E2 supplementation led to an unexpected decrease in: TFAM protein levels, in LPL, PPARγ and adiponectin gene expression and in the systemic HMW adiponectin levels. This decrease is probably due to the down-regulation of the ERα mRNA expression to avoid an over-stimulation by E2.
authors.affiliation: Grup Metabolisme Energètic i Nutrició, Departament de Biologia Fonamental i Ciències de la Salut, Institut Universitari d'Investigació en Ciències de la Salut, Universitat de les Illes Balears, Palma de Mallorca, Spain. emi.amengual@uib.es
authors.forename: Emilia
authors.initials: E
authors.lastname: Amengual-Cladera
authors.forename: Isabel
authors.initials: I
authors.lastname: Lladó
authors.forename: Magdalena
authors.initials: M
authors.lastname: Gianotti
authors.forename: Ana M
authors.initials: AM
authors.lastname: Proenza
mesh_terms: D052242:Adiponectin / Q000235:genetics*; D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D015415:Biomarkers / Q000378:metabolism; D001786:Blood Glucose / Q000378:metabolism; D001835:Body Weight / Q000187:drug effects; D004958:Estradiol / Q000097:blood / Q000494:pharmacology*; D047628:Estrogen Receptor alpha / Q000235:genetics; D047629:Estrogen Receptor beta / Q000235:genetics; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects*; D006706:Homeostasis / Q000187:drug effects; D020249:Hormone Replacement Therapy; D007333:Insulin Resistance; D050152:Intra-Abdominal Fat / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D008071:Lipoprotein Lipase / Q000235:genetics; D008928:Mitochondria / Q000187:drug effects* / Q000378:metabolism; D010052:Ovariectomy; D047495:PPAR gamma / Q000235:genetics; D050050:Protein Carbonylation / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D012727:Sex Characteristics
chemical_list: D052242:Adiponectin; D000975:Antioxidants; D015415:Biomarkers; D001786:Blood Glucose; D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D047495:PPAR gamma; D004958:Estradiol; D008071:Lipoprotein Lipase