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Characterization of NPY receptors controlling lipolysis and leptin secretion in human adipocytes
Author(s) -
Serradeil-Le Gal Claudine,
Lafontan Max,
Raufaste Danielle,
Marchand Jean,
Pouzet Brigitte,
Casellas Pierre,
Pascal Marc,
Maffrand Jean-Pierre,
Le Fur Gérard
Publication year - 2000
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(00)01649-5
Subject(s) - neuropeptide y receptor , peptide yy , receptor , leptin , medicine , endocrinology , adipocyte , chemistry , leptin receptor , secretion , lipolysis , adipose tissue , biology , neuropeptide , obesity
In order to characterize neuropeptide Y (NPY) receptors present in human adipocytes, we used selective ligands together with specific molecular probes able to recognize the different NPY receptor subtypes. RT‐PCR experiments revealed the presence of Y 1 receptor transcripts with Y 4 and Y 5 and absence of Y 2 signals. Binding studies, using selective radioiodinated ligands, detected a high number ( B max =497±124 fmol/mg protein) of a high affinity binding site only with [ 125 I]peptide YY (PYY) and [ 125 I](Leu 31 ,Pro 34 )PYY. These sites exhibited a typical Y 1 profile as indicated by the rank order of affinity of NPY analogs and the high affinity of two selective NPY receptor antagonists, SR120819A and BIBP3226. In [ 35 S]GTPγS binding experiments, PYY activation was totally inhibited by SR120819A and BIBP3226. Both compounds antagonized, with similar efficiency, the antilipolytic effect exerted by NPY in isolated adipocytes. Finally, PYY and Y 1 ligands enhanced adipocyte leptin secretion, an effect totally prevented by SR120819A. Thus, highly expressed in human adipocytes, the Y 1 receptor sustains the strong antilipolytic effect of NPY and exerts a positive action on leptin secretion.