title: Responses of brown adipose tissue activity to unloading in rats.
abstract: To study the responses of thermogenic activity in brown adipose tissue (BAT) to unloading, male Wistar rats were hindlimb suspended for 10 days. Compared with control rats, a significant increase in the BAT-to-body mass ratio and considerable differences in chemical components in BAT were observed in the hindlimb-suspended rats. These findings indicate a marked increase in the thermogenic capacity in BAT of the experimental group. Likewise, the thermogenic activity (which was assessed by guanosine 5'-diphosphate binding to BAT mitochondria) was markedly greater in the mitochondria recovered from BAT of the hindlimb-suspended rats than in those from the control rats (1,610 +/- 450 vs. 202 +/- 132 pmol recovered). Moreover, the uncoupling protein content in the BAT mitochondrial fraction of the hindlimb-suspended rats was significantly higher (1.6-fold) than that in the control rats. As was expected, the uncoupling protein mRNA expression was greater in hindlimb-suspended rats than in control animals. These results suggest that chronic hindlimb suspension leads to an increase in both the thermogenic capacity and the activity in BAT of rats.
authors.affiliation: Department of Hygiene, National Defense Medical College, Tokorozawa, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Yamashita
authors.forename: Y
authors.initials: Y
authors.lastname: Ohira
authors.forename: T
authors.initials: T
authors.lastname: Wakatsuki
authors.forename: M
authors.initials: M
authors.lastname: Yamamoto
authors.forename: T
authors.initials: T
authors.lastname: Kizaki
authors.forename: S
authors.initials: S
authors.lastname: Oh-ishi
authors.forename: Y
authors.initials: Y
authors.lastname: Sato
authors.forename: H
authors.initials: H
authors.lastname: Ohno
mesh_terms: D002001:Adipose Tissue, Brown / Q000502:physiology*; D000818:Animals; D015153:Blotting, Western; D001833:Body Temperature Regulation / Q000502:physiology; D001835:Body Weight / Q000502:physiology; D002352:Carrier Proteins / Q000378:metabolism; D004247:DNA / Q000096:biosynthesis; D004591:Electrophoresis, Polyacrylamide Gel; D006153:Guanosine Diphosphate / Q000378:metabolism; D007473:Ion Channels; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism; D024101:Mitochondrial Proteins; D015345:Oligonucleotide Probes; D011506:Proteins / Q000378:metabolism; D012313:RNA / Q000096:biosynthesis; D051381:Rats; D017208:Rats, Wistar; D000071256:Uncoupling Protein 1; D014893:Weightlessness / Q000009:adverse effects*; D018474:Weightlessness Simulation
chemical_list: D002352:Carrier Proteins; D007473:Ion Channels; D008565:Membrane Proteins; D024101:Mitochondrial Proteins; D015345:Oligonucleotide Probes; D011506:Proteins; D000071256:Uncoupling Protein 1; D006153:Guanosine Diphosphate; D012313:RNA; D004247:DNA