Skeletal muscle VO2 on-kinetics: set by O2 delivery or by O2 utilization? New insights into an old issue.
Skeletal muscle VO2 on-kinetics: set by O2 delivery or by O2 utilization? New insights into an old issue.
复制标题
骨骼肌 VO2 动力学：由 O2 输送量或 O2 利用量决定？
DOI：
10.1097/00005768-200001000-00017
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发表时间：
2000
影响因子：
4.1
通讯作者：
Grassi,B
中科院分区：
文献类型：
--
作者：
Grassi,B
GRASSI, B. 骨骼肌 VO2 动力学：由 O2 输送或 O2 利用决定？对老问题的新见解。医学。科学。体育锻炼，卷。 32，第 1 期，第 108-116 页，2000 年。我们小组最近进行的工作扩展了与肺和骨骼肌吸氧 (VO2) 动力学相关的一些基本问题的知识。我们证明，在从空载踩踏到低于通气阈值的负载踩踏过渡期间锻炼人类时，肺泡摄氧量动态可以视为骨骼肌摄氧量动态的相当接近。对原位分离的狗腓肠肌进行的实验表明，在从休息到收缩（对应于 70% 肌肉峰值 VO2）的转换过程中，对流 O2 输送到肌肉、肌内血流量 (Q) 与 VO2 分布不均以及外周 O2 扩散并不是骨骼肌 VO2 动力学的限制因素。因此，后者似乎主要由骨骼肌氧化代谢的内在惰性决定，可能与线粒体内乙酰基的可用性、与磷酸肌酸分裂相关的细胞内呼吸的调节作用有关，和/或与其他尚未精确识别的控制机制有关。文献证据表明，骨骼肌摄氧量动力学的限制因素可能根据肌肉收缩或运动的强度而变化。
GRASSI, B. Skeletal muscle VO2 on-kinetics: set by O2 delivery or by O2 utilization? New insights into an old issue. Med. Sci. Sports Exerc., Vol. 32, No. 1, pp. 108–116, 2000. Recent work conducted by our group has expanded knowledge on some basic issues related to pulmonary and skeletal muscle O2 uptake (VO2) on-kinetics. We demonstrated that, in exercising humans during transitions from unloaded pedaling to loaded pedaling below the ventilatory threshold, alveolar VO2 on-kinetics can be taken as a rather close approximation of skeletal muscle VO2 on-kinetics. Experiments conducted on the isolated in situ dog gastrocnemius preparation have shown that, during transitions from rest to contractions corresponding to 70% of the muscle peak VO2, convective O2 delivery to muscle, intramuscular blood flow (Q) versus VO2 maldistribution, and peripheral O2 diffusion are not limiting factors for skeletal muscle VO2 on-kinetics. The latter, therefore, appears to be mainly determined by an intrinsic inertia of skeletal muscle oxidative metabolism, possibly related to acetyl group availability within mitochondria, to regulatory effects on intracellular respiration related to phosphocreatine splitting, and/or to other still not precisely identified control mechanism (s). Evidence from the literature suggests that the limiting factors for skeletal muscle VO2 on-kinetics may vary according to the intensity of muscular contractions or of exercise.