Turku PET Centre, PO Box 52, FIN-20521 Turku, Finland.
J Appl Physiol (1985). 2012 Mar;112(6):1059-63. doi: 10.1152/japplphysiol.00732.2011. Epub 2012 Jan 5.
Regulation of subcutaneous adipose tissue blood flow (ATBF) remains poorly elucidated in humans, especially during exercise. In the present study we tested the role of adenosine in the regulation of ATBF adjacent to active and inactive thigh muscles during intermittent isometric knee-extension exercise (1 s contraction followed by 2 s rest with workloads of 50, 100, and 150 N) in six healthy young women. ATBF was measured using positron emission tomography (PET) without and with unspecific adenosine receptor inhibitor theophylline infused intravenously. Adipose regions were localized from fused PET and magnetic resonance images. Blood flow in subcutaneous adipose tissue adjacent to active muscle increased from rest (1.0 ± 0.3 ml·100 g(-1)·min(-1)) to exercise (P < 0.001) and along with increasing exercise intensity (50 N = 4.1 ± 1.4, 100 N = 5.4 ± 1.8, and 150 N = 6.9 ± 3.0 ml·100 g(-1)·min(-1), P = 0.03 for the increase). In contrast, ATBF adjacent to inactive muscle remained at resting levels with all intensities (∼1.0 ± 0.5 ml·100 g(-1)·min(-1)). During exercise theophylline prevented the increase in ATBF adjacent to active muscle especially during the highest exercise intensity (50 N = 4.3 ± 1.8 ml·100 g(-1)·min(-1), 100 N = 4.0 ± 1.5 ml·100 g(-1)·min(-1), and 150 N = 4.9 ± 1.8 ml·100 g(-1)·min(-1), P = 0.06 for an overall effect) but had no effect on blood flow adjacent to inactive muscle or adipose blood flow in resting contralateral leg. In conclusion, we report in the present study that 1) blood flow in subcutaneous adipose tissue of the leg is increased from rest to exercise in an exercise intensity-dependent manner, but only in the vicinity of working muscle, and 2) adenosine receptor antagonism attenuates this blood flow enhancement at the highest exercise intensities.
在人体中，尤其是在运动过程中，对皮下脂肪组织血流量（ATBF）的调节仍然知之甚少。在本研究中，我们在六名健康年轻女性中测试了腺苷在间歇性等长膝关节伸展运动（1 秒收缩，随后 2 秒休息，负荷为 50、100 和 150 N）时对活动和不活动大腿肌肉附近 ATBF 的调节作用。使用正电子发射断层扫描（PET）测量 ATBF，同时静脉内输注非特异性腺苷受体抑制剂茶碱。脂肪区域从融合的 PET 和磁共振图像中定位。与休息时相比，活动肌肉附近的皮下脂肪组织血流增加（P < 0.001），并随着运动强度的增加而增加（50 N = 4.1 ± 1.4，100 N = 5.4 ± 1.8，和 150 N = 6.9 ± 3.0 ml·100 g(-1)·min(-1)，P = 0.03 表示增加）。相比之下，不活动肌肉附近的 ATBF 在所有强度下仍保持在休息水平（约 1.0 ± 0.5 ml·100 g(-1)·min(-1)）。在运动过程中，茶碱尤其在最高运动强度时阻止了活动肌肉附近 ATBF 的增加（50 N = 4.3 ± 1.8 ml·100 g(-1)·min(-1)，100 N = 4.0 ± 1.5 ml·100 g(-1)·min(-1)，和 150 N = 4.9 ± 1.8 ml·100 g(-1)·min(-1)，P = 0.06 表示总体效果），但对不活动肌肉附近的血流或休息时对侧腿部的脂肪血流没有影响。总之，我们在本研究中报告，1）腿部皮下脂肪组织的血流从休息状态到运动状态以运动强度依赖的方式增加，但仅在活动肌肉附近，2）腺苷受体拮抗作用可减弱在最高运动强度时的这种血流增强作用。
