Reduced norepinephrine turnover in brown adipose tissue of pre-obese mice treated with monosodium-L-glutamate.
Norepinephrine (NE) turnover, an index of sympathetic nervous system (SNS) activity, was measured in interscapular brown adipose tissue (IBAT), heart and pancreas of 3-weeks-old pre-obese monosodium-L-glutamate (MSG) mice and at 6-weeks-old mildly obese MSG mice. In IBAT, rates of NE turnover were slower not only in 3-weeks-old MSG mice but also in older obese MSG mice than in their saline controls. In heart, rates of NE turnover were slower in 6-weeks-old mildly obese MSG mice, but not in pre-obese MSG mice. No significant difference in NE turnover in pancreas was observed at either age. The low NE turnover in IBAT of MSG-treated mice prior to the onset of gross obesity suggests that low SNS activity may be an initial contributor to their high energy efficiency and resultant obesity.
D002001:Adipose Tissue, Brown / Q000378:metabolism*; D000818:Animals; D001831:Body Temperature; D004435:Eating; D005260:Female; D005971:Glutamates / Q000627:therapeutic use*; D051379:Mice; D009206:Myocardium / Q000378:metabolism; D009638:Norepinephrine / Q000378:metabolism*; D009765:Obesity / Q000188:drug therapy* / Q000378:metabolism; D010179:Pancreas / Q000378:metabolism; D012970:Sodium Glutamate / Q000627:therapeutic use*
D005971:Glutamates; D012970:Sodium Glutamate; D009638:Norepinephrine