Characterizing rapid-onset vasodilation to single muscle contractions in the human leg.
Characterizing rapid-onset vasodilation to single muscle contractions in the human leg.
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将快速发生的血管舒张表征为人类腿部的单块肌肉收缩。
DOI：
10.1152/japplphysiol.00785.2014
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
Fadel,PaulJ
中科院分区：
文献类型：
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作者：
Credeur,DanielP;Holwerda,SethW;Restaino,RobertM;King,PhillipM;Crutcher,KieraL;Laughlin,MHarold;Padilla,Jaume;Fadel,PaulJ
单次肌肉收缩后的快速血管舒张（ROV）已在人类前臂中进行了研究，但尚未在腿部中进行表征。鉴于手臂和腿部之间已知的血管差异，我们试图描述ROV在腿部单个肌肉收缩后的特征。16名健康男性在其最大自主收缩（MVC）的5、10、20、40和60%进行随机有序的单次收缩，使用腿在心脏水平上下的等距膝关节伸展，并将这些与前臂的单次等距收缩（握力）进行比较。利用单股袖带压缩（300 mmHg）来估计腿部ROV的机械贡献。双多普勒超声检测连续血流量，手指光体积描记仪（Finometer）检测血压。单次等距膝伸肌收缩产生的腿部血管传导峰值强度依赖性增加，在心脏水平以上和心脏水平以下位置均显著大于前臂（例如，心脏水平以上：腿部20% MVC， +138±28% vs.手臂20% MVC， +89±17%；P< 0.05）。大腿袖带压缩也产生明显的充血反应，但与腿部单次等长收缩相比，这些反应短暂且幅度较小。总的来说，这些数据表明，腿部存在快速而强大的血管舒张到单个肌肉收缩，这在很大程度上独立于机械因素，从而使腿部成为研究人类ROV的可行模型。
Rapid-onset vasodilation (ROV) following single muscle contractions has been examined in the forearm of humans, but has not yet been characterized in the leg. Given known vascular differences between the arm and leg, we sought to characterize ROV following single muscle contractions in the leg. Sixteen healthy men performed random ordered single contractions at 5, 10, 20, 40, and 60% of their maximum voluntary contraction (MVC) using isometric knee extension made with the leg above and below heart level, and these were compared with single isometric contractions of the forearm (handgrip). Single thigh cuff compressions (300 mmHg) were utilized to estimate the mechanical contribution to leg ROV. Continuous blood flow was determined by duplex-Doppler ultrasound and blood pressure via finger photoplethysmography (Finometer). Single isometric knee extensor contractions produced intensity-dependent increases in peak leg vascular conductance that were significantly greater than the forearm in both the above- and below-heart level positions (e.g., above heart level: leg 20% MVC, +138 ± 28% vs. arm 20% MVC, +89 ± 17%;P< 0.05). Thigh cuff compressions also produced a significant hyperemic response, but these were brief and smaller in magnitude compared with single isometric contractions in the leg. Collectively, these data demonstrate the presence of a rapid and robust vasodilation to single muscle contractions in the leg that is largely independent of mechanical factors, thus establishing the leg as a viable model to study ROV in humans.