School of Biomedical Sciences, University of Nottingham Medical School, Queen's Medical Centre, Nottingham NG7 2UH, United Kingdom.
J Appl Physiol (1985). 2012 Jan;112(2):272-8. doi: 10.1152/japplphysiol.00807.2011. Epub 2011 Nov 3.
Reduced skeletal muscle free coenzyme A (CoASH) availability may decrease the contribution of fat oxidation to ATP production during high-intensity, submaximal exercise or, alternatively, limit pyruvate dehydrogenase complex (PDC) flux and thereby carbohydrate oxidation. Here we attempted to increase the muscle CoASH pool in humans, via pantothenic acid and cysteine feeding, in order to elucidate the role of CoASH availability on muscle fuel metabolism during exercise. On three occasions, eight healthy male volunteers (age 22.9 ± 1.4 yr, body mass index 24.2 ± 1.5 kg/m(2)) cycled at 75% maximal oxygen uptake (Vo(2max)) to exhaustion, followed by a 15-min work output performance test. Muscle biopsies were obtained at rest, and after 60 min and 91.3 ± 3.1 min of exercise (time to exhaustion on baseline visit) on each occasion. Two weeks following the first visit (baseline), 1 wk of oral supplementation with either 3 g/day of a placebo control (glucose polymer; CON) or 1.5 g/day each of d-pantothenic acid and l-cysteine (CP) was carried out prior to the second and third visits in a randomized, counterbalanced, double-blind manner, leaving a 3-wk gap in total between each visit. Resting muscle CoASH content was not altered by supplementation in any visit. Following 60 min of exercise, muscle CoASH content was reduced by 13% from rest in all three visits (P < 0.05), and similar changes in the respiratory exchange ratio, glycogenolysis (∼235 mmol/kg dry muscle), PCr degradation (∼57 mmol/kg dry muscle), and lactate (∼25 mmol/kg dry muscle) and acetylcarnitine (∼12 mmol(.)kg/dry muscle) accumulation was observed during exercise when comparing visits. Furthermore, no difference in work output was observed when comparing CON and CP. Acute feeding with pantothenic acid and cysteine does not alter muscle CoASH content and consequently does not impact on muscle fuel metabolism or performance during exercise in humans.
骨骼肌游离辅酶 A（CoASH）含量降低可能会减少高强度、亚最大运动中脂肪氧化对 ATP 生成的贡献，或者限制丙酮酸脱氢酶复合物（PDC）的流量，从而限制碳水化合物的氧化。在这里，我们试图通过泛酸和半胱氨酸喂养来增加人体肌肉中的 CoASH 池，以阐明 CoASH 供应在运动过程中对肌肉燃料代谢的作用。在三种情况下，八名健康男性志愿者（年龄 22.9 ± 1.4 岁，体重指数 24.2 ± 1.5 kg/m2）以 75%的最大摄氧量（Vo(2max））进行自行车运动至力竭，随后进行 15 分钟的工作输出性能测试。在每次情况下，在休息时以及运动 60 分钟后和 91.3 ± 3.1 分钟（基础访问时的力竭时间）时获得肌肉活检。在第一次访问（基础）后的两周内，以随机、对照、双盲的方式进行为期 1 周的口服补充，每天补充 3 克安慰剂对照（葡萄糖聚合物；CON）或每天补充 1.5 克 d-泛酸和 l-半胱氨酸（CP），总共在每个访问之间留出 3 周的间隔。在任何一次访问中，补充都不会改变休息时的肌肉 CoASH 含量。在运动 60 分钟后，所有三次访问中肌肉 CoASH 含量均从休息时减少了 13%（P < 0.05），并且在呼吸交换比、糖原分解（约 235 mmol/kg 干肌肉）、PCr 降解（约 57 mmol/kg 干肌肉）、乳酸（约 25 mmol/kg 干肌肉）和乙酰肉碱（约 12 mmol/kg 干肌肉）的积累方面观察到类似的变化。此外，在比较访问时，CON 和 CP 之间的工作输出没有差异。急性补充泛酸和半胱氨酸不会改变肌肉 CoASH 含量，因此不会影响运动中肌肉的燃料代谢或性能。
