González-Alonso José, Mortensen Stefan P, Jeppesen Tina D, Ali Leena, Barker Horace, Damsgaard Rasmus, Secher Niels H, Dawson Ellen A, Dufour Stéphane P
Centre for Sports Medicine and Human Performance, Brunel University, Uxbridge, Middlesex UB8 PH3, UK.
J Physiol. 2008 May 1;586(9):2405-17. doi: 10.1113/jphysiol.2008.152058. Epub 2008 Mar 13.
The muscle pump and muscle vasodilatory mechanism are thought to play important roles in increasing and maintaining muscle perfusion and cardiac output ((.)Q) during exercise, but their actual contributions remain uncertain. To evaluate the role of the skeletal muscle pump and vasodilatation on cardiovascular function during exercise, we determined leg and systemic haemodynamic responses in healthy men during (1) incremental one-legged knee-extensor exercise, (2) step-wise femoral artery ATP infusion at rest, (3) passive exercise (n=10), (4)femoral vein or artery ATP infusion (n=6), and (5) cyclic thigh compressions at rest and during passive and voluntary exercise (n=7). Incremental exercise resulted in progressive increases in leg blood flow (DeltaLBF 7.4 +/- 0.7 l min(-1)), cardiac output (Delta (.)Q 8.7 +/- 0.7 l min(-1)), mean arterial pressure (DeltaMAP 51 +/- 5 mmHg), and leg and systemic oxygen delivery and (.)VO2 . Arterial ATP infusion resulted in similar increases in (.)Q , LBF, and systemic and leg oxygen delivery, but central venous pressure and muscle metabolism remained unchanged and MAP was reduced. In contrast,femoral vein ATP infusion did not alter LBF, (.)Q or MAP. Passive exercise also increased blood flow (DeltaLBF 0.7 +/- 0.1 l min(-1)), yet the increase in muscle and systemic perfusion, unrelated to elevations in aerobic metabolism, accounted only for approximately 5% of peak exercise hyperaemia.Likewise, thigh compressions alone or in combination with passive exercise increased blood flow (DeltaLBF 0.5-0.7 l min(-1)) without altering (.)Q, MAP or (.)VO2. These findings suggest that the skeletal muscle pump is not obligatory for sustaining venous return, central venous pressure,stroke volume and (.)Q or maintaining muscle blood flow during one-legged exercise in humans.Further, its contribution to muscle and systemic peak exercise hyperaemia appears to be minimal in comparison to the effects of muscle vasodilatation.
肌肉泵和肌肉血管舒张机制被认为在运动过程中增加和维持肌肉灌注及心输出量（(.)Q）方面发挥着重要作用，但其实际贡献仍不确定。为了评估骨骼肌泵和血管舒张在运动期间对心血管功能的作用，我们测定了健康男性在以下情况下的腿部和全身血流动力学反应：(1) 递增式单腿伸膝运动；(2) 静息时逐步股动脉注射ATP；(3) 被动运动（n = 10）；(4) 股静脉或股动脉注射ATP（n = 6）；以及(5) 在静息、被动运动和主动运动期间进行周期性大腿压迫（n = 7）。递增运动导致腿部血流量（DeltaLBF 7.4 ± 0.7 l min⁻¹）、心输出量（Delta(.)Q 8.7 ± 0.7 l min⁻¹）、平均动脉压（DeltaMAP 51 ± 5 mmHg）以及腿部和全身氧输送及(.)VO₂逐渐增加。动脉注射ATP导致(.)Q、LBF以及全身和腿部氧输送出现类似增加，但中心静脉压和肌肉代谢保持不变，且MAP降低。相比之下，股静脉注射ATP未改变LBF、(.)Q或MAP。被动运动也增加了血流量（DeltaLBF 0.7 ± 0.1 l min⁻¹），然而，与有氧代谢升高无关的肌肉和全身灌注增加仅占运动高峰充血量的约5%。同样，单独或与被动运动相结合的大腿压迫增加了血流量（DeltaLBF 0.5 - 0.7 l min⁻¹），而未改变(.)Q、MAP或(.)VO₂。这些发现表明，在人类单腿运动期间，骨骼肌泵对于维持静脉回流、中心静脉压、每搏输出量和(.)Q或维持肌肉血流量并非必不可少。此外，与肌肉血管舒张的作用相比，其对肌肉和全身运动高峰充血量的贡献似乎极小。
