Gender- and site-related effects on lipolytic capacity of rat white adipose tissue.
Gender- and site-related differences in the lipolytic capacity, at the different steps of the adrenergic pathway, in gonadal and inguinal white adipose tissue (WAT), were assessed by studying alpha2A-adrenergic receptor (AR), beta3-AR and hormone-sensitive lipase (HSL) protein levels, and by determining the lipolytic response to different agents. Gonadal WAT showed a lower alpha2A/beta3-AR ratio, a greater lipolytic capacity in response to AR agonists, and higher HSL activity and protein levels than inguinal WAT. In female rats, we found greater alpha2A-AR protein levels and alpha2A/beta3-AR ratio compared to their male counterparts, but, on the other hand, a higher lipolytic response to beta-AR agonists and a greater lipolytic capacity at the postreceptor level, including a more activated HSL protein. Thus, the lipolytic capacity was clearly higher in gonadal than in inguinal WAT, at the different steps of the adrenergic pathway studied. Moreover, in both tissues, females showed a greater inhibition of lipolysis via alpha2-AR, which was counteracted by the higher lipolytic capacity at the postreceptor level.
Pujol
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Grup de metabolisme energètic i nutrició, Departament de Biologia Fonamental i Ciències de la Salut, Universitat de les Illes Balears, Cra. Valldemossa km 7.5, 07122 Palma de Mallorca, Spain.
Rodríguez-Cuenca
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S
Frontera
M
M
Justo
R
R
Lladó
I
I
Kraemer
F B
FB
Gianotti
M
M
Roca
P
P
D000273:Adipose Tissue / Q000033:anatomy & histology / Q000378:metabolism*; D000818:Animals; D003576:Electron Transport Complex IV / Q000378:metabolism; D005260:Female; D007473:Ion Channels; D050356:Lipid Metabolism; D008297:Male; D026901:Membrane Transport Proteins; D024101:Mitochondrial Proteins; D011506:Proteins / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D018341:Receptors, Adrenergic, alpha-2 / Q000378:metabolism*; D022702:Receptors, Adrenergic, beta-3 / Q000378:metabolism*; D012727:Sex Characteristics; D002787:Sterol Esterase / Q000378:metabolism*; D014475:Uncoupling Agents / Q000378:metabolism; D000071246:Uncoupling Protein 2
C547770:Adra2a protein, rat; D007473:Ion Channels; D026901:Membrane Transport Proteins; D024101:Mitochondrial Proteins; D011506:Proteins; D018341:Receptors, Adrenergic, alpha-2; D022702:Receptors, Adrenergic, beta-3; D014475:Uncoupling Agents; D000071246:Uncoupling Protein 2; D003576:Electron Transport Complex IV; D002787:Sterol Esterase