Effect of rhythmic tetanic skeletal muscle contractions on peak muscle perfusion
Effect of rhythmic tetanic skeletal muscle contractions on peak muscle perfusion
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DOI：
10.1152/japplphysiol.00339.2002
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发表时间：
2003-01-01
影响因子：
3.3
通讯作者：
Gladden, LB
中科院分区：
文献类型：
--
作者：
Dobson, JL;Gladden, LB
本研究的目的是通过犬腓肠肌原位自发灌注，研究节律性强直骨骼肌收缩对峰值肌肉灌注的影响。通过放置在腘动脉和静脉中的换能器测量同时脉动血压，并通过放置在静脉回流管中的流通型传输时间超声探头测量脉动流。进行了两个系列的实验。在系列1中，通过注入含有腺苷的生理盐水溶液引起肌肉血管床的最大血管舒张（29.3 mg/min）和硝普钠（180 μ g/min）持续15 s，然后同时闭塞腘动脉和静脉5 min。闭塞的释放引发最大充血反应，在此期间，用超最大电压（6- 8V，0.2-ms刺激，持续200-ms，50 Hz，1/s）诱导四次强直收缩。在系列2中，在肌肉收缩停止3秒的时间段之前刺激肌肉3分钟;然后恢复刺激。系列1的结果表明，虽然收缩降低了静脉压，但肌肉血流量在收缩开始时从2，056 +/- 246显著降低到1，738 +/- 225 min，然后在收缩停止后的前5 s内显著增加到1，925 +/- 225 ml. kg（-1）.min（-1）。ml.kg在系列2中，收缩3分钟后的血流量平均为1，454 +/-149 ml.kg（-1）.min（-1）。停止宫缩3秒导致血流量显著增加至1，874 +/- 172 ml.kg（-1）.min（-1）;当宫缩恢复时，血流量显著下降至1，458 +/- 139 mL.kg（-1）.min（-1）。我们的结论是，有节奏的，同步的，最大等长强直骨骼肌收缩的机械作用抑制峰值肌肉灌注在最大和接近最大的血管舒张的肌肉的血管床。这与肌泵在达到骨骼肌血流量峰值中的主要作用不同。
The purpose of this investigation was to examine the effect of rhythmic tetanic skeletal muscle contractions on peak muscle perfusion by using spontaneously perfused canine gastrocnemii in situ. Simultaneous pulsatile blood pressures were measured by means of transducers placed in the popliteal artery and vein, and pulsatile flow was measured with a flow-through-type transit-time ultrasound probe placed in the venous return line. Two series of experiments were performed. In series 1, maximal vasodilation of the muscles' vascular beds was elicited by infusing a normal saline solution containing adenosine (29.3 mg/min) and sodium nitroprusside (180 mug/min) for 15 s and then simultaneously occluding both the popliteal artery and vein for 5 min. The release of occlusion initiated a maximal hyperemic response, during which time four tetanic contractions were induced with supramaximal voltage (6-8 V, 0.2-ms stimuli for 200-ms duration at 50 Hz, 1/s). In series 2, the muscles were stimulated for 3 min before the muscle contractions were stopped for a period of 3 s; stimulation was then resumed. The results of series 1 indicate that, although contractions lowered venous pressure, muscle blood flow was significantly reduced from 2,056 +/- 246 to 1,738 +/- 225 ml.kg(-1).min(-1) when contractions were initiated and then increased significantly to 1,925 +/- 225 ml.kg(-1).min(-1) during the first 5 s after contractions were stopped. In series 2, blood flow after 3 min of contractions averaged 1,454 +/- 149 ml.kg(-1).min(-1). Stopping the contractions for 3 s caused blood flow to increase significantly to 1,874 +/- 172 ml.kg(-1).min(-1); blood flow declined significantly to 1,458 +/- 139 ml.kg(-1).min(-1) when contractions were resumed. We conclude that the mechanical action of rhythmic, synchronous, maximal isometric tetanic skeletal muscle contractions inhibits peak muscle perfusion during maximal and near-maximal vasodilation of the muscle's vascular bed. This argues against a primary role for the muscle pump in achieving peak skeletal muscle blood flow.