Tissue-specific regulation of fat cell lipolysis by NPY in 6-OHDA-treated rats.
The effects of neuropeptide Y (NPY), peptide YY (PYY), [Leu31, Pro34]NPY, and NPY (13-36) on adipocyte lipolysis have been studied in subcutaneous (inguinal) and visceral (parametrial) rat adipose tissues. A 48-h fasting period and chemical sympathectomy were used to evaluate the regulation of Y1 and Y2 pathways in rat adipocytes. NPY, PYY, and [Leu31, Pro34]NPY significantly inhibited fat cell lipolysis by about 25% in both tissues (p < or = 0.05). This inhibition was achieved mainly through the Y1 pathway. No significant response to NPY (13-36) was observed, suggesting a lack of involvement of the Y2 pathway in the antilipolytic effect of NPY and PYY. The 48-h fasting period led to the loss of the Y1 inhibitory effect previously observed in control rats. On the other hand, the chemical sympathectomy induced a 35% increase of fat cell lipolysis (p < or = 0.05). The latter involved the Y2 pathway as stimulated by NPY (13-36), and was observed in the parametrial tissue exclusively. These results suggest that: a) rat Y receptors reported to exhibit Gi responses can also express Gs-like responses, and b) visceral and subcutaneous adipose tissues exhibit specific regulation of fat cell lipolysis.
Labelle
M
M
INRS-Santé, Université du Québec à Montréal, Canada.
Boulanger
Y
Y
Fournier
A
A
St Pierre
S
S
Savard
R
R
D017667:Adipocytes / Q000166:cytology / Q000187:drug effects*; D000818:Animals; D019167:Appetite Stimulants / Q000494:pharmacology*; D001835:Body Weight / Q000187:drug effects; D048429:Cell Size / Q000187:drug effects; D004435:Eating / Q000187:drug effects; D005215:Fasting; D005260:Female; D008066:Lipolysis / Q000187:drug effects*; D009478:Neuropeptide Y / Q000031:analogs & derivatives / Q000494:pharmacology*; D016627:Oxidopamine / Q000494:pharmacology*; D010446:Peptide Fragments / Q000494:pharmacology; D019894:Peptide YY / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D017476:Receptors, Neuropeptide Y / Q000187:drug effects / Q000502:physiology; D013563:Sympathectomy, Chemical; D013565:Sympatholytics / Q000494:pharmacology*
D019167:Appetite Stimulants; D009478:Neuropeptide Y; D010446:Peptide Fragments; D017476:Receptors, Neuropeptide Y; D013565:Sympatholytics; C062924:neuropeptide Y (13-36); C097212:neuropeptide Y-Y1 receptor; C095889:neuropeptide Y2 receptor; D019894:Peptide YY; C062259:neuropeptide Y, Leu(31)-Pro(34)-; D016627:Oxidopamine