Effect of endurance training on adrenergic control of lipolysis in adipose tissue of obese women.
The effect of a 12-wk training program on sc abdominal adipose tissue (SCAAT) was studied in 11 obese women. Before and after the training, biopsies of SCAAT were performed for mRNA levels determination. Using the microdialysis method, involvement of alpha(2)- and beta-adrenergic receptor (ARs) in the control of lipolysis in SCAAT was studied using local perfusion of epinephrine alone or supplemented with phentolamine, an alpha(2)-AR antagonist. In addition, the variation in dialysate glycerol concentrations during exercise (50% peak oxygen consumption at 40 min) in a probe perfused with Ringer's solution was compared with that obtained in a probe perfused with Ringer's solution plus phentolamine. Training did not promote changes in the expression of key genes of the lipolytic pathway. The epinephrine-induced rise in the dialysate glycerol concentration was identical before and after training and was similarly potentiated by phentolamine. During exercise, the potentiating effect of phentolamine on the glycerol response was apparent before, but not after, training. The exercise-induced increase in plasma norepinephrine was lower after training (P = 0.04). In conclusion, training did not modify either the expression of genes involved in the control of lipolysis or alpha(2)- and beta-ARs in situ sensitivity to epinephrine in SCAAT. Training reduced the antilipolytic action of catecholamines mediated by alpha(2)-ARs during exercise, probably due to a reduction of exercise-induced catecholamine increase.
Franco-Czech Laboratory for Clinical Research on Obesity, French Institute of Health and Medical Research, Institut National de la Santé et de la Recherche Médicale, Unité 586, and Third Faculty of Medicine, Charles University, Prague, Czech Republic.
B
B
Richterova
V
V
Stich
C
C
Moro
J
J
Polak
E
E
Klimcakova
M
M
Majercik
I
I
Harant
N
N
Viguerie
F
F
Crampes
D
D
Langin
M
M
Lafontan
M
M
Berlan
D000005:Abdomen; D000273:Adipose Tissue / Q000502:physiology*; D000322:Adrenergic Agonists / Q000008:administration & dosage / Q000097:blood; D000328:Adult; D001786:Blood Glucose; D015992:Body Mass Index; D004837:Epinephrine / Q000008:administration & dosage / Q000097:blood; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005260:Female; D015870:Gene Expression / Q000502:physiology; D005990:Glycerol / Q000097:blood; D006801:Humans; D007328:Insulin / Q000097:blood; D008066:Lipolysis / Q000187:drug effects / Q000502:physiology; D009638:Norepinephrine / Q000097:blood; D009765:Obesity / Q000503:physiopathology*; D010101:Oxygen Consumption / Q000502:physiology; D010807:Physical Endurance / Q000502:physiology*; D012333:RNA, Messenger / Q000032:analysis; D018341:Receptors, Adrenergic, alpha-2 / Q000235:genetics* / Q000378:metabolism; D011943:Receptors, Adrenergic, beta / Q000235:genetics* / Q000378:metabolism; D012146:Rest / Q000502:physiology; D020133:Reverse Transcriptase Polymerase Chain Reaction
D000322:Adrenergic Agonists; D001786:Blood Glucose; D005230:Fatty Acids, Nonesterified; D007328:Insulin; D012333:RNA, Messenger; D018341:Receptors, Adrenergic, alpha-2; D011943:Receptors, Adrenergic, beta; D005990:Glycerol; D009638:Norepinephrine; D004837:Epinephrine