Leptin immunoexpression and innervation in rat interscapular brown adipose tissue of cold-acclimated rats: the effects of L-arginine and L-NAME.
The aim of the present study was to explore the effect of nitric oxide on leptin immunoexpression and innervation in interscapular brown adipose tissue (IBAT) of room- and cold- acclimated rats. Animals acclimated both to room-temperature (22 +/- 1 degrees C) and cold (4 +/- 1 degrees C) were treated with L-arginine, a substrate for nitric oxide synthases (NOSs), or N?-nitro-L-arginine methyl ester (L-NAME), an inhibitor of NOSs, for 45 days. Leptin expression and localization in brown adipocytes was studied by immunohistochemistry, and innervation stained by the Bodian method. Strong leptin immunopositivity was observed in brown adipocytes cytoplasm of all room-acclimated groups, but nuclear leptin positivity was found only in L-NAME treated rats. In cold-acclimated control and L-NAME treated rats leptin immunopositivity was absent, while L-arginine treatment reversed the cold-induced suppression of leptin expression. Comparing to control, L-arginine, and even more L-NAME, at 22 +/- 1 degrees C induced greater innervation. In conclusion, L-arginine treatment changes leptin expression pattern on cold in rat IBAT.
Korac
Aleksandra
A
Faculty of Biology, University of Belgrade, Belgrade, Serbia. sankor@bf.bio.bg.ac.yu
Buzadzic
Biljana
B
Petrovic
Vesna
V
Vasilijevic
Ana
A
Jankovic
Aleksandra
A
Korac
Bato
B
D000064:Acclimatization / Q000187:drug effects*; D002001:Adipose Tissue, Brown / Q000166:cytology / Q000187:drug effects* / Q000294:innervation*; D000818:Animals; D001120:Arginine / Q000494:pharmacology*; D003080:Cold Temperature; D007150:Immunohistochemistry; D020738:Leptin / Q000378:metabolism*; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D051381:Rats
D020738:Leptin; D001120:Arginine; D019331:NG-Nitroarginine Methyl Ester