Sexual dimorphism in the adrenergic control of rat brown adipose tissue response to overfeeding.
Gender-related differences in the brown adipose tissue (BAT) response to overfeeding rats on a cafeteria diet were studied by assessing the balance between the expression of beta-adrenoceptors (beta1-, beta2-, beta3-AR) and alpha2A-AR and their relation to the expression of uncoupling proteins (UCP1, UCP2, UCP3). Cafeteria diet feeding for 15 days, which involved a similar degree of hyperphagia in both sexes, led to a greater body weight excess in females than in males and a lower activation of thermogenesis. Gender-related differences were found for different adrenoceptor expression and protein levels, which might explain, in part, sex differences in the thermogenic parameters. The lower expression of alpha2A-AR in females than in males could be responsible for the higher expression of UCP1 and thermogenic capacity under non-hyperphagic conditions. However, in a situation of high adrenergic stimulation--as occurs with overfeeding--as there is a preferential recruitment of the beta3-AR by noradrenaline compared with other adrenergic receptors, the higher levels of beta3-AR in males rats than in females could be responsible for the greater thermogenic capacity and the lesser weight gain in males. Thus, the alpha2/beta3 balance in BAT could be a key in the thermogenic control.
Rodríguez
E
E
Departament de Biologia Molecular, Nutricó i Biotecnologia, Universitat de les Illes Balears, Palma de Mallorca, Spain.
Monjo
M
M
Rodríguez-Cuenca
S
S
Pujol
E
E
Amengual
B
B
Roca
P
P
Palou
A
A
D002001:Adipose Tissue, Brown / Q000737:chemistry / Q000502:physiology*; D000818:Animals; D002352:Carrier Proteins / Q000235:genetics; D004032:Diet; D004435:Eating / Q000502:physiology*; D005260:Female; D015870:Gene Expression / Q000502:physiology; D007473:Ion Channels; D008297:Male; D008565:Membrane Proteins / Q000235:genetics; D026901:Membrane Transport Proteins; D024101:Mitochondrial Proteins; D009765:Obesity / Q000235:genetics / Q000503:physiopathology; D011506:Proteins / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar; D018341:Receptors, Adrenergic, alpha-2 / Q000032:analysis / Q000235:genetics*; D011943:Receptors, Adrenergic, beta / Q000032:analysis / Q000235:genetics*; D012727:Sex Characteristics; D000071256:Uncoupling Protein 1; D000071246:Uncoupling Protein 2; D000071247:Uncoupling Protein 3
D002352:Carrier Proteins; D007473:Ion Channels; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D024101:Mitochondrial Proteins; D011506:Proteins; D012333:RNA, Messenger; D018341:Receptors, Adrenergic, alpha-2; D011943:Receptors, Adrenergic, beta; C000604373:Ucp1 protein, rat; C000604391:Ucp2 protein, rat; C000604394:Ucp3 protein, rat; D000071256:Uncoupling Protein 1; D000071246:Uncoupling Protein 2; D000071247:Uncoupling Protein 3