The effect of acute cold exposure and norepinephrine on uncoupling protein gene expression in brown adipose tissue of monosodium glutamate-obese mice.
Abnormal regulation of mitochondrial uncoupling protein (UCP) gene expression was studied in brown adipose tissue (BAT) of monosodium glutamate (MSG)-induced obese mice. UCP mRNA levels in control mice increased markedly after acute cold exposure; however, MSG-obese mice showed an impaired response. In contrast, an injection of norepinephrine (NE) induced a comparable increase in UCP mRNA levels in control and MSG-obese mice. These results suggest that the impairment in the cold-induced increase in UCP mRNA is due to a deficient sympathetic input to BAT and/or to a diminished response of BAT to endogenous NE, which constitutes the mechanism of impaired thermoregulation in obese mice in a cold environment.
Department of Pharmacology, Tokyo Women's Medical University, School of Medicine, Japan.
F
F
Tsukahara
Y
Y
Uchida
K
K
Ohba
A
A
Ogawa
T
T
Yoshioka
T
T
Muraki
D002001:Adipose Tissue, Brown / Q000187:drug effects* / Q000378:metabolism; D000818:Animals; D002352:Carrier Proteins / Q000235:genetics*; D003080:Cold Temperature; D005786:Gene Expression Regulation / Q000187:drug effects; D007473:Ion Channels; D008565:Membrane Proteins / Q000235:genetics*; D051379:Mice; D008928:Mitochondria / Q000378:metabolism; D024101:Mitochondrial Proteins; D009638:Norepinephrine / Q000494:pharmacology*; D009765:Obesity / Q000139:chemically induced / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012970:Sodium Glutamate / Q000633:toxicity*; D000071256:Uncoupling Protein 1
D002352:Carrier Proteins; D007473:Ion Channels; D008565:Membrane Proteins; D024101:Mitochondrial Proteins; D012333:RNA, Messenger; D000071256:Uncoupling Protein 1; D012970:Sodium Glutamate; D009638:Norepinephrine