Rate-limiting factors of oxygen uptake kinetics during exercise

运动过程中摄氧动力学的速率限制因素

• 批准号: 13680070
• 负责人: KOGA Shunsaku
• 金额: $ 2.18万
• 依托单位: Kobe Design University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13680070/
• 关键词: oxygen uptake kinetics; oxygen delivery; oxygen utilization; slow component; 運動開始時

The knee extensor (KE) exercise model engenders different muscle and fiber recruitment patterns, blood flow and energetic responses compared with conventional cycle ergometry (CE). This investigation tested the hypotheses that: 1) upright two-leg KE and CE in the same subjects would yield fundamentally different pulmonary oxygen uptake (pVo_2) dynamics (H_1), and 2) pulmonary and muscle Vo_2 (mVo_2) kinetics for KE would be mechanistically linked (and therefore similar)(H_2). Six subjects performed KE and CE transitions from unloaded to moderate (<ventilatory threshold, VT) and heavy (>VT) exercise. In addition to pVo_2 during CE and KE, simultaneous pulsed and echo Doppler methods, combined with blood sampling from the femoral vein, were utilized to quantify the precise temporal profiles of femoral artery blood flow (LBF) and mVo_2 at the onset of KE. H_1: The gain (amplitude/work rate) of the fast component of pVo_2 for both moderate and heavy exercise was higher during KE (〜12ml/W/min) compared with CE (〜10), but the time constants for the fast component did not differ. Further, the mean response time (MRT) and the contribution of the slow component to the overall response for heavy KE were significantly greater than for CE. H_2: The time constant for the component of mVo_2. Moreover, the slow component of pVo_2 evident for the heavy KE reflected the gradual increase in mVo_2. The initial LBF kinetics following onset of KE were significantly faster than the phase 2 pVo_2 kinetics (moderate: time constant LBF = 8.0 ^^+__- 3.5s, pVo_2 = 32.7 ^^+__- 5.6 s, P<0.05; heavy: LBF = 9.7 ^^+__- 2.0 s, pVo_2 = 29.9 ^^+__- 7.9 s, P<0.05). The MRT of LBF was also significantly faster than that of pVo_2. These data demonstrate similar time constants but a greater gain for pVo_2 dynamics of KE vs. CE. In addition, for KE there was a striking dissociation between the temporal profiles of muscle blood flow and pVo_2 during KE.

膝伸肌（KE）运动模型产生不同的肌肉和纤维招募模式，血流量和精力充沛的反应相比，传统的自行车测力计（CE）。本研究验证了以下假设：（1）同一受试者直立双腿KE和CE会产生根本不同的肺氧摄取（pVo_2）动力学（H_1）;（2）KE的肺和肌肉Vo_2（mVo_2）动力学在机械上是联系的（因此是相似的）（H_2）。6名受试者进行KE和CE从无负荷到中度（<呼吸阈值，VT）和重度（>VT）运动的转换。除CE和KE期间的pVo_2外，还利用同步脉冲和回波多普勒方法，结合股静脉采血，定量测定KE开始时股动脉血流（LBF）和mVo_2的精确时间曲线。H_1：中、重度运动时pVo_2快成分的增益（振幅/功率）在KE（12 ml/W/min）时均高于CE（10 ml/W/min），但快成分的时间常数无差异。此外，平均反应时间（MRT）和缓慢的组成部分的整体反应重KE的贡献显着大于CE。H_2：mVo_2分量的时间常数。此外，pVo_2的慢分量对于重KE是明显的，反映了mVo_2的逐渐增加。KE开始后的初始LBF动力学明显快于2相pVo_2动力学（中度：时间常数LBF = 8.0 ^^+_- 3.5s，pVo_2 = 32.7 ^^+_-5.6s，P<0.05;重度：LBF = 9.7 ^^+_-2.0s，pVo_2 = 29.9 ^^+_-7.9s，P<0.05）。LBF的MRT也明显快于pVo_2。这些数据表明类似的时间常数，但更大的增益为pVo_2动力学KE与CE。此外，对于KE，在KE过程中，肌肉血流量的时间曲线与pVo_2之间存在显著的分离。

项目成果

Behnke, B., S.Koga et al.: "Dynamics of microvascular oxygen pressure across the rest-exercise transition in rat skeletal muscle"Respiration Physiology. 126・1. 53-63 (2001)

Behnke, B., S.Koga 等：“大鼠骨骼肌休息-运动过渡期间的微血管氧压动态”呼吸生理学 126・1 (2001)。

Fukuda, Y., S.Koga他: "VO_2 kinetics in heavy exercise is not altered by prior exercise with a different muscle group"Journal of Applied Physiology. 92. 2467-2474 (2002)

Fukuda, Y., S.Koga 等人：“重度运动中的 VO_2 动力学不会因先前使用不同肌肉群的运动而改变”应用生理学杂志 92. 2467-2474 (2002)。

Fukuba, Y., S.Koga他: "Vo_2 kinetics in heavy exercise is not altered by prior exercise with a different muscle group"Journal of Applied Physiology. 92. 2467-2474 (2003)

Fukuba, Y., S.Koga 等人：“重度运动中的 Vo_2 动力学不会因之前使用不同肌肉群的运动而改变”应用生理学杂志 92. 2467-2474 (2003)。

Y.Fukuba., S.Koga., et al.: "Vo_2 kinetics in heavy exercise is not altered by prior exercise with a different muscle group"Journal of Applied Physiology. 92. 2467-2474 (2002)

Y.Fukuba.、S.Koga. 等人：“剧烈运动中的 Vo_2 动力学不会因之前使用不同肌肉群的运动而改变”《应用生理学杂志》。

Fukuba, Y., S.Koga et al.: "V_<02> kinetics in heavy exercise is not altered by prior exercise with a different muscle group"Journal of Applied Physiology. (印刷中). (2002)

Fukuba, Y., S.Koga 等人：“重度运动中的 V_<02> 动力学不会因先前使用不同肌肉群的运动而改变”应用生理学杂志（2002 年出版）。