Skeletal muscle blood flow and flow heterogeneity during dynamic and isometric exercise in humans
Skeletal muscle blood flow and flow heterogeneity during dynamic and isometric exercise in humans
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DOI：
10.1152/ajpheart.00714.2002
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发表时间：
2003-03-01
影响因子：
4.8
通讯作者：
Knuuti, J
中科院分区：
文献类型：
--
作者：
Laaksonen, MS;Kalliokoski, KK;Knuuti, J
在七名接受过耐力训练的健康男性中研究了动态和间歇性等距膝关节伸展运动对骨骼肌血流和血流异质性的影响。使用正电子发射断层扫描 (PET) 和 [O-15]H2O 示踪剂测量区域肌肉血流量，并在次最大间歇等长和动态运动期间记录股四头肌 (QF) 肌肉的肌电 (EMG) 活动。动态运动期间 QF 血流量增加 61% (P = 0.002)。有趣的是，与间歇等长运动相比，动态运动期间的血流不均匀性降低了 13% (P = 0.024)。动态运动期间肌电图活动显着升高（P < 0.001），并且从等长运动到动态运动肌电图活动的变化与股外侧肌血流变化密切相关（r = 0.98，P < 0.001），但与股直肌无关（r = -0.09，P = 0.942）。总之，在相同运动强度下，动态运动比间歇性等长运动产生更高且更不均匀的血流。这些反应至少部分与肌电图活动的增加有关。
The effects of dynamic and intermittent isometric knee extension exercises on skeletal muscle blood flow and flow heterogeneity were studied in seven healthy endurance-trained men. Regional muscle blood flow was measured using positron emission tomography (PET) and an [O-15]H2O tracer, and electromyographic (EMG) activity was recorded in the quadriceps femoris (QF) muscle during submaximal intermittent isometric and dynamic exercises. QF blood flow was 61% (P = 0.002) higher during dynamic exercise. Interestingly, flow heterogeneity was 13% (P = 0.024) lower during dynamic compared with intermittent isometric exercise. EMG activity was significantly higher (P < 0.001) during dynamic exercise, and the change in EMG activity from isometric to dynamic exercise was tightly related to the change in blood flow in the vastus lateralis muscle (r = 0.98, P < 0.001) but not in the rectus femoris muscle (r = -0.09, P = 0.942). In conclusion, dynamic exercise causes higher and less heterogeneous blood flow than intermittent isometric exercise at the same exercise intensity. These responses are, at least partly, related to the increased EMG activity.