Relationship between hypothalamic noradrenergic activity and the sympathetic activity in interscapular brown adipose tissue after cold-swim stress in rats
Noradrenaline (NA) activities in both hypothalamus and interscapular brown adipose tissue (IBAT) were simultaneously assessed before and after cold-swim stress in rats. The technique of gas chromatography-mass spectrometry was employed for the analysis of NA and its primary neuronal metabolite, 3,4-dehydroxy-phenylethylenglycol (DHPG), and the ratio of DHPG to NA was used as an index of NA activity. The ratios of DHPG/NA in both hypothalamus and IBAT were significantly elevated 5 and 20 min after cold-swim stress. Moreover, we found that there is a highly significant positive relationship between the hypothalamic DHPG/NA ratio and the ratio of DHPG/NA in IBAT (r = 0.872, p less than 0.0001). This observation strongly supports the concept in which hypothalamic NA neurons play an important role in modulating the sympathetic outflow.
|ISBN||0024-3205 (Print) 0024-3205 (Linking)|
|Authors||Gotoh, M.; Smythe, G. A.; Iguchi, A.|
|Publisher Name||LIFE SCIENCES|
|URL link to publisher's version||http://www.ncbi.nlm.nih.gov/pubmed/1522754|