Rapid vasodilation within contracted skeletal muscle in humans: new insight from concurrent use of diffuse correlation spectroscopy and Doppler ultrasound
Rapid vasodilation within contracted skeletal muscle in humans: new insight from concurrent use of diffuse correlation spectroscopy and Doppler ultrasound
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DOI：
10.1152/ajpheart.00761.2020
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发表时间：
2021-02-01
影响因子：
4.8
通讯作者：
Ono，Yumie
中科院分区：
文献类型：
--
作者：
Ichinose，Masashi;Nakabayashi，Mikie;Ono，Yumie
先前的研究表明，即使在依赖肢体内的肌肉短暂收缩后，管道动脉血流量也会迅速增加。然而，这种快速充血是否发生在人类收缩的骨骼肌中还有待证实。因此，我们使用扩散相关光谱（DCS）来表征人体肌肉收缩引起的肌肉微血管内的快速充血和血管舒张反应。25名健康男性志愿者在20%、40%、60%和80%的最大随意收缩下进行单次1秒等长握杆。将DCS探针放置在指浅屈肌上，并连续导出骨骼肌血流指数（SMBFI）。同时，用多普勒超声测量肱动脉血流（BABF）反应。单次肌肉收缩诱发快速，单相增加SMBFI和BABF发生在3秒内释放收缩后。初始和峰值响应随着收缩强度的增加而增加，并且在所有强度下BABF均大于SMBFI。BABF在收缩结束后5 ~ 8 s内达高峰。SMBFI在BABF通过其峰值后继续增加，并向静息水平下降，并在收缩完成后约10至15 s达到峰值。我们的结论是，单肌肉收缩引起快速，强度依赖性充血收缩骨骼肌微血管内。此外，骨骼肌微血管的快速充血和血管舒张反应的特征不同于在上游管道动脉中同时评估的那些特征。收缩的骨骼肌微血管和上游导管动脉内的强度依赖性充血。我们还表明，骨骼肌微血管内的收缩引起的快速充血和血管舒张反应的幅度和时间过程显着不同的管道动脉。
Previous studies showed that conduit artery blood flow rapidly increases after even a brief contraction of muscles within the dependent limb. Whether this rapid hyperemia occurs within contracted skeletal muscle in humans has yet to be confirmed, however. We therefore used diffuse correlation spectroscopy (DCS) to characterize the rapid hyperemia and vasodilatory responses within the muscle microvasculature induced by single muscle contractions in humans. Twenty-five healthy male volunteers performed single 1-s isometric handgrips at 20%, 40%, 60%, and 80% of maximum voluntary contraction. DCS probes were placed on the flexor digitorum superficialis muscle, and a skeletal muscle blood flow index (SMBFI) was derived continuously. At the same time, brachial artery blood flow (BABF) responses were measured using Doppler ultrasound. Single muscle contractions evoked rapid, monophasic increases in both SMBFI and BABF that occurred within 3 s after release of contraction. The initial and peak responses increased with increases in contraction intensity and were greater for BABF than for SMBFI at all intensities. BABF reached its peak within 5 to 8 s after the end of contraction. The SMBFI continued to increase after the BABF passed its peak and was decreasing toward the resting level and peaked about 10 to 15 s after completion of the contraction. We conclude that single muscle contractions induce rapid, intensity-dependent hyperemia within the contracted skeletal muscle microvasculature. Moreover, the characteristics of the rapid hyperemia and vasodilatory responses of skeletal muscle microvessels differ from those simultaneously evaluated in the upstream conduit artery.NEW & NOTEWORTHYThrough the concurrent use of diffuse correlation spectroscopy and Doppler ultrasound, we provide the first evidence in humans that a single brief muscle contraction evokes rapid, intensity-dependent hyperemia within the contracted skeletal muscle microvasculature and the upstream conduit artery. We also show that the magnitude and time course of the contraction-induced rapid hyperemia and vasodilatory responses within skeletal muscle microvessels significantly differ from those in the conduit artery.