The effects of L-arginine and L-NAME supplementation on redox-regulation and thermogenesis in interscapular brown adipose tissue.
Changes in inducible nitric oxide synthase (iNOS) protein levels and its relationship with the hyperplasia and uncoupling protein 1 (UCP1) levels were examined in interscapular brown adipose tissue (IBAT) of adult rat males receiving L-arginine (L-Arg; 2.25%) or N-nitro-L-arginine methyl ester (L-NAME; 0.01%) as a drinking liquid and maintained at low (4+/-1 degrees C) or room (22+/-1 degrees C) temperature for 45 days. Cold generally diminished both iNOS immunopositivity and protein level in IBAT, as well as the rate of apoptosis. Among groups acclimated to cold, higher iNOS immunopositivity and protein levels were detected only in the L-Arg-treated group. Furthermore, chronic L-Arg treatment increased IBAT mass and UCP1 protein content, while L-NAME had an opposite effect, decreasing both IBAT mass and UCP1 protein level, as compared to the control maintained at 4+/-1 degrees C. These data suggest that nitric oxide (NO) produced by iNOS could also contribute to overall NO-associated regulation of thermogenesis in IBAT. Namely, that iNOS, i.e. NO, in correlation with enhanced thermogenesis, additionally induced IBAT hyperplasia and UCP1 level compared to that induced by low temperature. Cooperative action of decreased apoptosis accompanied by increased tissue hyperplasia and UCP1 level, observed in IBAT of cold-acclimated rats, would be a way of meeting the metabolic requirements for increased thermogenesis.
Petrović
Vesna
V
Department of Physiology, Institute for Biological Research, Sinisa Stanković, University of Belgrade, Belgrade, Serbia and Montenegro.
Korać
Aleksandra
A
Buzadzić
Biljana
B
Korać
Bato
B
D000064:Acclimatization / Q000502:physiology; D002001:Adipose Tissue, Brown / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology; D001120:Arginine / Q000494:pharmacology*; D015153:Blotting, Western; D002352:Carrier Proteins / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D005978:Glutathione / Q000378:metabolism; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling; D007473:Ion Channels; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism*; D024101:Mitochondrial Proteins; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology*; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism*; D051381:Rats / Q000502:physiology*; D013482:Superoxide Dismutase / Q000378:metabolism; D013696:Temperature; D022722:Thermogenesis / Q000187:drug effects / Q000502:physiology*; D000071256:Uncoupling Protein 1
D002352:Carrier Proteins; D007473:Ion Channels; D008565:Membrane Proteins; D024101:Mitochondrial Proteins; C000604373:Ucp1 protein, rat; D000071256:Uncoupling Protein 1; D001120:Arginine; D052247:Nitric Oxide Synthase Type II; D013482:Superoxide Dismutase; D005978:Glutathione; D019331:NG-Nitroarginine Methyl Ester