Leptin-induced lipolysis opposes the tonic inhibition of endogenous adenosine in white adipocytes
The aim of the present study was to gain insight into the signaling pathway used by leptin to stimulate lipolysis. The lipolytic rate of white adipocytes from sex- and age-matched lean (+/+) and fa/fa rats was determined in the absence or presence of leptin together with a number of agents acting at...
| Autores: | , , |
|---|---|
| Formato: | artículo |
| Fecha de publicación: | 2001 |
| País: | España |
| Recursos: | Universidad de Navarra |
| Repositorio: | Dadun. Depósito Académico Digital de la Universidad de Navarra |
| Idioma: | inglés |
| OAI Identifier: | oai:dadun.unav.edu:10171/23391 |
| Acesso em linha: | https://hdl.handle.net/10171/23391 |
| Access Level: | acceso abierto |
| Palavra-chave: | Adipose Tissue/cytology/metabolism Bucladesine/pharmacology Lipolysis/drug effects/physiology |
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Leptin-induced lipolysis opposes the tonic inhibition of endogenous adenosine in white adipocytesFrühbeck, G. (Gema)|||/items/7f0b1f72-bc91-4ab0-a3fd-21e9a3fb663bGomez-Ambrosi, J. (Javier)|||/items/21d09997-940a-45f7-9b4b-0a9f64b2ed8eSalvador-Rodríguez, F.J. (Francisco Javier)|||/items/1175815b-412b-41a6-b91f-6dbfa349f9c8Adipose Tissue/cytology/metabolismBucladesine/pharmacologyLipolysis/drug effects/physiologyThe aim of the present study was to gain insight into the signaling pathway used by leptin to stimulate lipolysis. The lipolytic rate of white adipocytes from sex- and age-matched lean (+/+) and fa/fa rats was determined in the absence or presence of leptin together with a number of agents acting at different levels of the signaling cascade. Leptin did not modify FSK-, dbcAMP-, and IBMX-stimulated lipolysis. Lipolysis can also be maximally stimulated by lowering media adenosine levels with adenosine deaminase (ADA), i.e., in the ligand-free state. Although ADA produced near maximal lipolysis in adipocytes of lean animals, only half of the maximal lipolytic rate (50.9+/-3.2%) was achieved in fat cells from fa/fa rats (P=0.0034). In adipocytes from lean animals preincubated with ADA, leptin caused a concentration-related stimulation of lipolysis (P=0.0001). However, leptin had no effect on the lipolytic activity of adipocytes in the ligand-free state from fa/fa rats. The adenosine A1 receptor agonist CPA effectively inhibited basal lipolysis in both lean and obese adipocytes (P=0.0001 and P=0.0090, respectively). Leptin had no effect on the lipolytic rate of adipocytes isolated from fa/fa rats and preincubated with CPA. When adipocytes were incubated with the A1 receptor antagonist DPCPX, a significant increase in glycerol release was observed in fa/fa fat cells (P=0.009), whereas cells isolated from lean rats showed no differences to ADA-stimulated lipolysis. After pretreatment with PTX, which inactivates receptor-mediated Gi function, adipocytes of obese rats became as responsive to the stimulatory actions of ISO as cells from lean rats (P=0.0090 vs. ISO in fa/fa rats; P=0.2416 vs. lean rats, respectively). PTX treatment of lean cells, however, did not alter their response to this lipolytic agent. It can be concluded that the lipolytic effect of leptin is located at the adenylate cyclase/Gi proteins level and that leptin-induced lipolysis opposes the tonic inhibition of endogenous adenosine in white adipocytes.Federation of American Society of Experimental BiologyDadun. Depósito Académico Digital Universidad de Navarra20122012-10-1620012001-01-0120012001-01-01journal articlehttp://purl.org/coar/resource_type/c_6501info:eu-repo/semantics/articleapplication/pdfhttps://hdl.handle.net/10171/23391reponame:Dadun. Depósito Académico Digital de la Universidad de Navarrainstname:Universidad de NavarraInglésengopen accesshttp://purl.org/coar/access_right/c_abf2info:eu-repo/semantics/openAccessoai:dadun.unav.edu:10171/233912026-06-21T12:47:57Z |
| dc.title.none.fl_str_mv |
Leptin-induced lipolysis opposes the tonic inhibition of endogenous adenosine in white adipocytes |
| title |
Leptin-induced lipolysis opposes the tonic inhibition of endogenous adenosine in white adipocytes |
| spellingShingle |
Leptin-induced lipolysis opposes the tonic inhibition of endogenous adenosine in white adipocytes Frühbeck, G. (Gema)|||/items/7f0b1f72-bc91-4ab0-a3fd-21e9a3fb663b Adipose Tissue/cytology/metabolism Bucladesine/pharmacology Lipolysis/drug effects/physiology |
| title_short |
Leptin-induced lipolysis opposes the tonic inhibition of endogenous adenosine in white adipocytes |
| title_full |
Leptin-induced lipolysis opposes the tonic inhibition of endogenous adenosine in white adipocytes |
| title_fullStr |
Leptin-induced lipolysis opposes the tonic inhibition of endogenous adenosine in white adipocytes |
| title_full_unstemmed |
Leptin-induced lipolysis opposes the tonic inhibition of endogenous adenosine in white adipocytes |
| title_sort |
Leptin-induced lipolysis opposes the tonic inhibition of endogenous adenosine in white adipocytes |
| dc.creator.none.fl_str_mv |
Frühbeck, G. (Gema)|||/items/7f0b1f72-bc91-4ab0-a3fd-21e9a3fb663b Gomez-Ambrosi, J. (Javier)|||/items/21d09997-940a-45f7-9b4b-0a9f64b2ed8e Salvador-Rodríguez, F.J. (Francisco Javier)|||/items/1175815b-412b-41a6-b91f-6dbfa349f9c8 |
| author |
Frühbeck, G. (Gema)|||/items/7f0b1f72-bc91-4ab0-a3fd-21e9a3fb663b |
| author_facet |
Frühbeck, G. (Gema)|||/items/7f0b1f72-bc91-4ab0-a3fd-21e9a3fb663b Gomez-Ambrosi, J. (Javier)|||/items/21d09997-940a-45f7-9b4b-0a9f64b2ed8e Salvador-Rodríguez, F.J. (Francisco Javier)|||/items/1175815b-412b-41a6-b91f-6dbfa349f9c8 |
| author_role |
author |
| author2 |
Gomez-Ambrosi, J. (Javier)|||/items/21d09997-940a-45f7-9b4b-0a9f64b2ed8e Salvador-Rodríguez, F.J. (Francisco Javier)|||/items/1175815b-412b-41a6-b91f-6dbfa349f9c8 |
| author2_role |
author author |
| dc.contributor.none.fl_str_mv |
Dadun. Depósito Académico Digital Universidad de Navarra |
| dc.subject.none.fl_str_mv |
Adipose Tissue/cytology/metabolism Bucladesine/pharmacology Lipolysis/drug effects/physiology |
| topic |
Adipose Tissue/cytology/metabolism Bucladesine/pharmacology Lipolysis/drug effects/physiology |
| description |
The aim of the present study was to gain insight into the signaling pathway used by leptin to stimulate lipolysis. The lipolytic rate of white adipocytes from sex- and age-matched lean (+/+) and fa/fa rats was determined in the absence or presence of leptin together with a number of agents acting at different levels of the signaling cascade. Leptin did not modify FSK-, dbcAMP-, and IBMX-stimulated lipolysis. Lipolysis can also be maximally stimulated by lowering media adenosine levels with adenosine deaminase (ADA), i.e., in the ligand-free state. Although ADA produced near maximal lipolysis in adipocytes of lean animals, only half of the maximal lipolytic rate (50.9+/-3.2%) was achieved in fat cells from fa/fa rats (P=0.0034). In adipocytes from lean animals preincubated with ADA, leptin caused a concentration-related stimulation of lipolysis (P=0.0001). However, leptin had no effect on the lipolytic activity of adipocytes in the ligand-free state from fa/fa rats. The adenosine A1 receptor agonist CPA effectively inhibited basal lipolysis in both lean and obese adipocytes (P=0.0001 and P=0.0090, respectively). Leptin had no effect on the lipolytic rate of adipocytes isolated from fa/fa rats and preincubated with CPA. When adipocytes were incubated with the A1 receptor antagonist DPCPX, a significant increase in glycerol release was observed in fa/fa fat cells (P=0.009), whereas cells isolated from lean rats showed no differences to ADA-stimulated lipolysis. After pretreatment with PTX, which inactivates receptor-mediated Gi function, adipocytes of obese rats became as responsive to the stimulatory actions of ISO as cells from lean rats (P=0.0090 vs. ISO in fa/fa rats; P=0.2416 vs. lean rats, respectively). PTX treatment of lean cells, however, did not alter their response to this lipolytic agent. It can be concluded that the lipolytic effect of leptin is located at the adenylate cyclase/Gi proteins level and that leptin-induced lipolysis opposes the tonic inhibition of endogenous adenosine in white adipocytes. |
| publishDate |
2001 |
| dc.date.none.fl_str_mv |
2001 2001-01-01 2001 2001-01-01 2012 2012-10-16 |
| dc.type.none.fl_str_mv |
journal article http://purl.org/coar/resource_type/c_6501 |
| dc.type.openaire.fl_str_mv |
info:eu-repo/semantics/article |
| format |
article |
| dc.identifier.none.fl_str_mv |
https://hdl.handle.net/10171/23391 |
| url |
https://hdl.handle.net/10171/23391 |
| dc.language.none.fl_str_mv |
Inglés eng |
| language_invalid_str_mv |
Inglés |
| language |
eng |
| dc.rights.none.fl_str_mv |
open access http://purl.org/coar/access_right/c_abf2 |
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info:eu-repo/semantics/openAccess |
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open access http://purl.org/coar/access_right/c_abf2 |
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openAccess |
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application/pdf |
| dc.publisher.none.fl_str_mv |
Federation of American Society of Experimental Biology |
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Federation of American Society of Experimental Biology |
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reponame:Dadun. Depósito Académico Digital de la Universidad de Navarra instname:Universidad de Navarra |
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Universidad de Navarra |
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Dadun. Depósito Académico Digital de la Universidad de Navarra |
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Dadun. Depósito Académico Digital de la Universidad de Navarra |
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1869407794964201472 |
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15,301603 |