Depot- and gender-related differences in the lipolytic pathway of adipose tissue from severely obese patients.
The present study was performed to analyze in detail gender- and site-related alterations in the adrenergic signal transduction pathway of lipolysis in fat cells isolated from subcutaneous abdominal and visceral fat depots from severely obese patients. The study group consisted of 30 morbidly obese subjects (9 men and 21 women) aged 41.1+/-1.9 years, with a body mass index (BMI) of 54.7+/-1.7 kg/m2, who had undergone abdominal surgery. Protein levels of hormone-sensitive lipase (HSL) and adrenergic receptors (AR), as well as HSL activity and the lipolytic response to adrenergic agents were analyzed. Both fat depots had similar basal lipolysis, but the capacity of catecholamines to activate lipolysis was greater in visceral fat, both at AR and postreceptor levels. Basal lipolysis and lipolytic activity induced by dibutyryl cyclic AMP were higher in men than in women. However, the visceral depot of women showed a higher maximal stimulation by noradrenaline than that of men, in accordance with higher beta1- and beta3-AR protein levels. In conclusion, the main gender-related differences were located in the visceral depot, with women exhibiting a higher sensitivity to catecholamines associated with an increased provision of beta-AR, while men showed an enhanced lipolytic capacity at the postreceptor level.
Ramis
Joana M
JM
Departament de Biologia Fonamental i Ciencies de la Salut, Institut Universitari d'Investigació en iencies de la Salut (IUNICS), and Servei d'Endocrinologia i Nutrició, Hospital Universitari Son Dureta, alma de Mallorca, Spain.
Salinas
Ramón
R
García-Sanz
José M
JM
Moreiro
José
J
Proenza
Ana M
AM
Lladó
Isabel
I
D050153:Abdominal Fat / Q000378:metabolism*; D017667:Adipocytes / Q000378:metabolism; D000273:Adipose Tissue / Q000378:metabolism* / Q000473:pathology; D000328:Adult; D015153:Blotting, Western; D015992:Body Mass Index; D003994:Bucladesine / Q000494:pharmacology; D005576:Colforsin / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D050152:Intra-Abdominal Fat / Q000378:metabolism*; D008066:Lipolysis; D008297:Male; D008875:Middle Aged; D009638:Norepinephrine / Q000494:pharmacology; D009767:Obesity, Morbid / Q000378:metabolism*; D011942:Receptors, Adrenergic, alpha / Q000032:analysis; D011943:Receptors, Adrenergic, beta / Q000032:analysis; D012737:Sex Factors; D002787:Sterol Esterase / Q000097:blood
D011942:Receptors, Adrenergic, alpha; D011943:Receptors, Adrenergic, beta; D005576:Colforsin; D003994:Bucladesine; D002787:Sterol Esterase; D009638:Norepinephrine