Polak J, Moro C, Klimcakova E, Hejnova J, Majercik M, Viguerie N, Langin D, Lafontan M, Stich V, Berlan M
Franco-Czech Laboratory for Clinical Research on Obesity, French Institute of Health and Medical Research (Inserm U586) and 3rd Faculty of Medicine, Charles University, Prague, Czech Republic.
Diabetologia. 2005 Dec;48(12):2631-40. doi: 10.1007/s00125-005-0003-8. Epub 2005 Nov 5.
AIMS/HYPOTHESIS: The aim of this study was to investigate whether dynamic strength training modifies the control of lipolysis, with particular attention paid to the involvement of the antilipolytic adrenergic alpha 2A receptor (ADRA2A) pathway.
Twelve obese men (age: 47.4+/-2.8 years; BMI: 32.7+/-0.9) were investigated during a 210-min euglycaemic-hyperinsulinaemic clamp conducted before and after 3 months of dynamic strength training. Before and during the third hour of the clamp, the lipolytic effect of a perfusion of isoproterenol or adrenaline (epinephrine) alone or associated with the ADRA2A antagonist phentolamine was evaluated using the microdialysis method of measuring extracellular glycerol concentration (EGC) in subcutaneous abdominal adipose tissue (SCAAT). In addition, biopsies of SCAAT were carried out before and after training to determine mRNA levels
The training increased insulin sensitivity in adipose tissue. The decrease of EGC was more pronounced during the clamp conducted after the training period than during the clamp done in pre-training conditions. Before and after the training, catecholamines induced an increase in EGC, the increase being lower during the clamp on each occasion. The isoproterenol-induced increase in EGC was higher after the training. Adrenaline-induced lipolysis was potentiated by phentolamine after but not before the training. There were no training-induced changes in mRNA levels of key genes of the lipolytic pathway in SCAAT.
CONCLUSIONS/INTERPRETATION: In obese subjects, dynamic strength training improves whole-body and adipose tissue insulin responsiveness. It increases responsiveness to the adrenergic beta receptor stimulation of lipolysis and to the antilipolytic action of catecholamines mediated by ADRA2As.
目的/假设：本研究旨在调查动态力量训练是否会改变脂肪分解的调控，尤其关注抗脂解肾上腺素能α2A受体（ADRA2A）途径的参与情况。
对12名肥胖男性（年龄：47.4±2.8岁；体重指数：32.7±0.9）在进行3个月动态力量训练前后分别进行一次持续210分钟的正常血糖-高胰岛素钳夹试验。在钳夹试验的第3小时开始前及期间，通过微透析法测量腹部皮下脂肪组织（SCAAT）中的细胞外甘油浓度（EGC），评估单独灌注异丙肾上腺素或肾上腺素（epinephrine），或联合ADRA2A拮抗剂酚妥拉明时的脂肪分解作用。此外，在训练前后取SCAAT组织活检以测定mRNA水平。
训练提高了脂肪组织中的胰岛素敏感性。与训练前钳夹试验期间相比，训练后钳夹试验期间EGC的降低更为明显。训练前后，儿茶酚胺均使EGC升高，但每次钳夹试验期间升高幅度较低。训练后异丙肾上腺素诱导的EGC升高幅度更大。训练后酚妥拉明增强了肾上腺素诱导的脂肪分解作用，而训练前未出现此现象。训练未引起SCAAT中脂肪分解途径关键基因mRNA水平的变化。
结论/解读：在肥胖受试者中，动态力量训练可改善全身及脂肪组织的胰岛素反应性。它增加了对肾上腺素能β受体刺激脂肪分解的反应性以及对由ADRA2A介导的儿茶酚胺抗脂解作用的反应性。
