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Role of venous blood flow from exercising muscles in regulation of circulation during exercise

运动肌肉的静脉血流在运动过程中循环调节中的作用

基本信息

批准号：
14580065
负责人：
KAGAYA Atsuko
金额：
$ 2.43万
依托单位：
Japan Women's College of Physical Education
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2003
项目状态：
已结题

项目摘要

The purpose of this study was to clarify the role of venous out flow in regulation of blood circulation during exercise. For this purpose, the blood flow was determined in brachial vein and artery during exercise. Six female subjects (age; 26.3±3.8 yrs) performed handgrip exercise of two different protocols in a supine position; 1) 5-s handgrip exercise at 10%, 30%, 50% and 70% MVC, 2) 1-min rhythmic handgrip exercise at 50% MVC, at the frequency of 15 times /min. Blood flow volume and velocity were measured using M-mode ultrasound and Doppler ultrasound methods. Blood pressure (Finapres) and muscle oxygenation (NIRS) in forearm muscles were measured simultaneously. Venous outflow increased at the onset of muscle contraction, whereas arterial inflow increased immediately after contraction. Significant blood flow changes with exercise intensity were found in artery but not in vein. When handgrip exercises were repeated for 1-mm both venous and arterial blood flow, and velocity fluctuated with muscle contraction and relaxation. They gradually increased with exercise duration after 20s. However, the increase in arterial and venous blood flow did not change in the similar manner, and the former exceeded significantly the latter and resulted in the increase in muscle blood volume in the exercising forearm muscles measured by NIRS. These results suggest that venous outflow from exercising muscle would be balanced with arterial inflow at the beginning of exercise at low intensity. When exercise intensity became higher and exercise duration was prolonged, they became to be out of balance and the blood volume in exercising muscles increased. The effect of blood volume increase on circulatory regulation during exercise remains to be studied.

本研究的目的是阐明静脉流出在运动中调节血液循环中的作用。为此目的，测定了运动过程中臂静脉和臂动脉的血流量。6名女性受试者(年龄26.3±3.8岁)在仰卧位进行两种不同的握力练习：1)10%、30%、50%和70%MVC的5-S握力练习；2)50%MVC的1min有节奏的握力练习，15次/min。用M型超声和多普勒超声测量血流流量和血流速度。同时测定前臂肌肉的血压(Finapres)和肌氧合(NIRS)。静脉流出在肌肉收缩开始时增加，而动脉流入在收缩后立即增加。随着运动强度的增加，动脉血流量变化明显，静脉血流量变化不明显。当握力练习重复1 mm时，静脉和动脉血流均出现波动，速度随肌肉收缩和放松而波动。20s以后随着运动时间的延长逐渐增加。然而，动脉和静脉血流量的增加没有类似的变化，前者明显超过后者，并导致NIRS测量的运动前臂肌肉血容量的增加。这些结果表明，在低强度运动开始时，运动肌肉的静脉流出与动脉流入将是平衡的。运动强度越大，运动持续时间越长，运动肌肉的血流量越大，平衡越失衡。运动中血容量增加对循环调节的影响还有待研究。