Effect of muscle acidity on muscle metabolism and fatigue during intense exercise in man
Effect of muscle acidity on muscle metabolism and fatigue during intense exercise in man
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DOI：
10.1113/jphysiol.1996.sp021618
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发表时间：
1996-09-01
影响因子：
5.5
通讯作者：
Richter, EA
中科院分区：
文献类型：
--
作者：
Bangsbo, J;Madsen, K;Richter, EA
1.本研究的目的是探讨肌肉pH值对肌肉代谢和疲劳发展的影响. 7名受试者在两种情况下进行了剧烈的腿部运动：之前进行和不进行剧烈的间歇性手臂运动，导致高或中等（对照）血乳酸浓度（分别为HL和C）。在每次运动前和运动后即刻，从m.活动腿的股外侧肌。在力竭运动前和力竭运动中分别测定下肢血流量，采集股动脉和股静脉血标本. HL患者的运动持续时间短于C患者（3.46 +/- 0.28 vs. 4.67 +/- 0.55 min;平均值+/- S.E.M.; P < 0.05）。运动前，C组和HL组肌肉pH值相同（7.17 vs.7.10），但运动结束时HL组肌肉pH值低于C组（6.82 vs.6.65; P < 0.05）。HL组运动时钾的释放量高于C组（P < 0.05），但力竭时HL组和C组的动脉和股静脉血浆钾浓度相同。HL组的肌肉乳酸浓度高于C组（3.7 +/- 0.4 vs. 1.6 +/- 0.2 mmol（kg湿重）（-1）; P < 0.05），但在力竭时相同（26.5 +/- 2.7 vs. 25.4 +/- 2.4 mmol（kg湿重）（-1））。HL中乳酸的总释放量低于C（18.7 +/- 4.5 vs. 50.4 +/- 11.0 mmol; P < 0.05），但乳酸产生速率无差异（9.0 +/- 1.0 vs. 10.2 +/- 1.3 mmol（kg净重）（-1）min（-1））。C组和HL组的肌糖原分解速率相同（8.1 +/- 1.2 vs. 8.2 +/- 1.0 mmol（kg湿重）（-1）min（-1））。5.目前的数据表明，肌肉酸度升高并不减少肌肉糖原分解/糖酵解，也不是人体剧烈运动时疲劳的唯一原因，相反，肌肉中钾的积累可能是疲劳发展的一个重要因素。
1. The aim of this study was to examine the effect of muscle pH on muscle metabolism and development of fatigue during intense exercise.2. Seven subjects performed intense exhaustive leg exercise on two occasions: with and without preceding intense intermittent arm exercise leading to high or moderate (control) blood lactate concentrations (HL and C, respectively). Prior to and immediately after each exercise bout, a muscle biopsy was taken from m. vastus lateralis of-the active leg. Leg blood flow was measured and femoral arterial and venous blood samples were collected before and frequently during the exhaustive exercises.3. The duration of the exercise was shorter in HL than in C (3.46 +/- 0.28 vs. 4.67 +/- 0.55 min; means +/- S.E.M.; P < 0.05). Before exercise muscle pH was the same in C and HL (7.17 vs. 7.10), but at the end of exercise muscle pH was lower in HL than in C (6.82 vs. 6.65; P < 0.05). The release of potassium during exercise was higher (P < 0.05) in HL compared with C, but the arterial and femoral venous plasma potassium concentrations were the same at exhaustion in HL and C.4. Muscle lactate concentration was higher in HL compared with C (3.7 +/- 0.4 vs. 1.6 +/- 0.2 mmol (kg wet weight)(-1); P < 0.05), but the same at exhaustion (26.5 +/- 2.7 vs. 25.4 +/- 2.4 mmol (kg wet weight)(-1)). Total release of lactate in HL was lower than in C (18.7 +/- 4.5 vs. 50.4 +/- 11.0 mmol; P < 0.05), but rate of lactate production was not different (9.0 +/- 1.0 vs. 10.2 +/- 1.3 mmol (kg net weight)(-1) min(-1)). The rate of muscle glycogen breakdown was the same in C and HL (8.1 +/- 1.2 vs. 8.2 +/- 1.0 mmol (kg wet weight)(-1) min(-1)).5. The present data suggest that elevated muscle acidity does not reduce muscle glycogenolysis/glycolysis and is not the only cause of fatigue during intense exercise in man. Instead, accumulation of potassium in muscle interstitium may be an important factor in the development of fatigue.