Maltais F, LeBlanc P, Simard C, Jobin J, Bérubé C, Bruneau J, Carrier L, Belleau R
Unité de Recherche, Centre de Pneumologie de l'Hôpital Laval, Québec, Canada.
Am J Respir Crit Care Med. 1996 Aug;154(2 Pt 1):442-7. doi: 10.1164/ajrccm.154.2.8756820.
The purpose of this study was to evaluate the physiologic responses to endurance training in patients with moderate to severe airflow obstruction by specifically looking at changes in skeletal muscle enzymatic activities. Eleven patients (age = 65 +/- 7 yr, mean +/- SD, FEV1 = 36 +/- 11% of predicted value, range = 24 to 54%) were evaluated before and after an endurance training program. Each evaluation included a percutaneous biopsy of the vastus lateralis and a stepwise exercise test on an ergocycle up to his/her maximal capacity. VE, VO2, VcO2, and serial arterial lactic acid concentration were measured during the exercise test. The activity of two oxidative enzymes, citrate synthase (CS) and 3-hydroxyacyl-CoA dehydrogenase (HADH), and of three glycolytic enzymes, lactate dehydrogenase, hexokinase, and phosphofructokinase was determined. The training consisted of 30-min exercise sessions on a calibrated ergocycle, 3 times a week for 12 wk. The aerobic capacity was severely reduced at baseline (VO2max = 54 +/- 12% of predicted) and increased by 14% after training (p < 0.05). For an identical exercise workload, there was a significant reduction in VE (34.5 +/- 10.0 versus 31.9 +/- 9.0 L/min, p < 0.05) and in arterial lactic acid concentration (3.4 +/- 1.3 versus 2.8 +/- 0.9 mmol/L, p < 0.01) after training. The lactate threshold also increased after training (p < 0.01) while the activity of the three glycolytic enzymes was similar at the two evaluations. In contrast, the activity of CS and HADH increased significantly after training (22.3 +/- 3.5 versus 25.8 +/- 3.8 mumol/min/g muscle for CS, p < 0.05, and 5.5 +/- 2.9 versus 7.7 +/- 2.5 mumol/min/g for HADH, p < 0.01). A significant inverse relationship was found between the percent changes in the activity of CS and HADH, and the percent changes in arterial lactic acid during exercise (p = 0.01). We conclude that endurance training can reduce exercise-induced lactic acidosis and improve skeletal muscle oxidative capacity in patients with moderate to severe chronic obstructive pulmonary disease (COPD).
本研究的目的是通过具体观察骨骼肌酶活性的变化，评估中重度气流阻塞患者对耐力训练的生理反应。对11例患者（年龄=65±7岁，均值±标准差，第一秒用力呼气容积[FEV1]=预测值的36±11%，范围=24%至54%）在耐力训练计划前后进行了评估。每次评估包括对股外侧肌进行经皮活检，以及在测力计上进行逐步运动测试直至其最大能力。在运动测试期间测量了每分钟静息通气量（VE）、摄氧量（VO2）、二氧化碳排出量（VcO2）和动脉血乳酸浓度系列值。测定了两种氧化酶，即柠檬酸合酶（CS）和3-羟酰基辅酶A脱氢酶（HADH），以及三种糖酵解酶，即乳酸脱氢酶、己糖激酶和磷酸果糖激酶的活性。训练包括在校准的测力计上进行30分钟的运动训练，每周3次，共12周。基线时有氧能力严重降低（最大摄氧量[VO2max]=预测值的54±12%），训练后增加了14%（p<0.05）。对于相同的运动负荷，训练后每分钟静息通气量显著降低（34.5±10.0与31.9±9.0升/分钟，p<0.05），动脉血乳酸浓度也显著降低（3.4±1.3与2.8±0.9毫摩尔/升，p<0.01）。训练后乳酸阈值也增加了（p<0.01），而在两次评估中三种糖酵解酶的活性相似。相比之下，训练后柠檬酸合酶和3-羟酰基辅酶A脱氢酶的活性显著增加（柠檬酸合酶：22.3±3.5与25.8±3.8微摩尔/分钟/克肌肉，p<0.05；3-羟酰基辅酶A脱氢酶：5.5±2.9与7.7±2.5微摩尔/分钟/克，p<0.01）。发现运动期间柠檬酸合酶和3-羟酰基辅酶A脱氢酶活性的百分比变化与动脉血乳酸的百分比变化之间存在显著的负相关（p=0.01）。我们得出结论，耐力训练可以减轻运动诱发的乳酸性酸中毒，并提高中重度慢性阻塞性肺疾病（COPD）患者的骨骼肌氧化能力。
