title: The obesity in bilateral ovariectomized rats is related to a decrease in the expression of leptin receptors in the brain.
abstract: We investigated the expression levels of leptin receptors in the brain of ovariectomized (OVX) rats. The mean expression level of ob mRNA in adipose tissues of OVX rats was significantly (P < 0.01) lower than that in the SHAM operation group rats, and the mean body weight of OVX rats was significantly (P < 0.01) greater than that in the SHAM group rats. However, there were no differences between serum leptin concentrations in these two groups. The mean level of leptin receptor (OB-R) mRNA expression in the brain tissue and the mean level of long form type OB-R (OB-RL) mRNA expression in the hypothalamus of the OVX rats were significantly (P < 0.05) lower than those in the SHAM group rats. These changes were cancelled by supplementation with 17 beta-estradiol in OVX rats. These results suggested that not only changes in the expression level of ob mRNA in adipose tissue and the serum leptin concentration but also changes in the OB-R mRNA in the brain are involved in the body weight increase in OVX rats and that a decrease in OB-R makes transmission of signals to suppress the amount of food intake difficult, thus leading to an increase in body weight.
authors.affiliation: Department of Obstetrics and Gynecology, University of Tokushima School of Medicine, Tokushima, Japan.
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Kimura
authors.forename: Minoru
authors.initials: M
authors.lastname: Irahara
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Yasui
authors.forename: Seiichiro
authors.initials: S
authors.lastname: Saito
authors.forename: Michiko
authors.initials: M
authors.lastname: Tezuka
authors.forename: Shuji
authors.initials: S
authors.lastname: Yamano
authors.forename: Masaharu
authors.initials: M
authors.lastname: Kamada
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Aono
mesh_terms: D000818:Animals; D001835:Body Weight; D001921:Brain / Q000378:metabolism*; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism*; D005260:Female; D015870:Gene Expression; D020738:Leptin / Q000097:blood; D009765:Obesity / Q000209:etiology* / Q000235:genetics / Q000378:metabolism*; D010052:Ovariectomy / Q000009:adverse effects; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D011956:Receptors, Cell Surface; D054411:Receptors, Leptin
chemical_list: D002352:Carrier Proteins; D020738:Leptin; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D054411:Receptors, Leptin