Decreased norepinephrine turnover rate in the brown adipose tissue of pre-obese fa/fa Zucker rats.
Norepinephrine (NE) content and turnover rate, and the activity of dopamine-beta-hydroxylase (DBH) were measured in the brown adipose tissue (BAT) of developing Zucker rats of the three genotypes: Fa/Fa and Fa/fa (with a lean phenotype) and fa/fa (phenotypically obese). As early as 15 days of age, namely at a pre-obese stage, BAT NE content and turnover rate are already reduced in fa/fa rats, just like they are at 50 days. The development of DBH activity is completely impaired in fa/fa rats. These results demonstrate that the reduction in sympathetic tone in BAT of fa/fa rats is already present before the onset of phenotypic obesity.
Laboratoire d'Endocrinologie, CNRS URA 1121, Université Paris-Sud, Orsay, France.
M F
MF
Blouquit
A
A
Geloën
H
H
Koubi
D
D
Edwards
D
D
Gripois
D002001:Adipose Tissue, Brown / Q000201:enzymology / Q000378:metabolism*; D000367:Age Factors; D000818:Animals; D004299:Dopamine beta-Hydroxylase / Q000378:metabolism*; D005260:Female; D005838:Genotype; D007700:Kinetics; D008297:Male; D008781:Methyltyrosines / Q000494:pharmacology; D009638:Norepinephrine / Q000378:metabolism*; D009765:Obesity / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D011924:Rats, Zucker; D019805:alpha-Methyltyrosine
D008781:Methyltyrosines; D019805:alpha-Methyltyrosine; D004299:Dopamine beta-Hydroxylase; D009638:Norepinephrine