Yoshida T, Udo M, Chida M, Ichioka M, Makiguchi K
Exercise Physiology Laboratory, Faculty of Health and Sport Sciences, Osaka University, Japan.
Eur J Appl Physiol Occup Physiol. 1989;58(7):772-7. doi: 10.1007/BF00637390.
The purpose of the present study was to investigate whether, in humans, hypoxia results in an elevated lactate production from exercising skeletal muscle. Under conditions of both hypoxia [inspired oxygen fraction (F1O2): 11.10%] and normoxia (F1O2: 20.94%), incremental exercise of a forearm was performed. The exercise intensity was increased every minute by 1.6 kg.m.min-1 until exhaustion. During the incremental exercise the partial pressure of oxygen (PO2) and carbon dioxide (PCO2), oxygen saturation (SO2), pH and lactate concentration [HLa] of five subjects, were measured repeatedly in blood from the brachial artery and deep veins from muscles in the forearm of both the active and inactive sides. The hypoxia (arterial SO2 approximately 70%) resulted in (1) the difference in [HLa] in venous blood from active muscle (values during exercise-resting value) often being more than twice that for normoxia, (2) a significantly greater difference in venous-arterial (v-a) [HLa] for the exercising muscle compared to normoxia, and (3) a difference in v-a [HLa] for non-exercising muscle that was slightly negative during normoxia and more so with hypoxia. These studies suggest that lower O2 availability to the exercising muscle results in increased lactate production.
本研究的目的是调查在人类中，低氧是否会导致运动的骨骼肌产生更多乳酸。在低氧（吸入氧分数：11.10%）和常氧（吸入氧分数：20.94%）条件下，对前臂进行递增运动。运动强度每分钟增加1.6 kg·m·min-1，直至疲劳。在递增运动期间，对五名受试者肱动脉和前臂两侧活动及非活动侧肌肉深静脉血液中的氧分压（PO2）、二氧化碳分压（PCO2）、氧饱和度（SO2）、pH值和乳酸浓度[HLa]进行反复测量。低氧（动脉SO2约为70%）导致：（1）活动肌肉静脉血中[HLa]的差异（运动时的值-静息值）常是常氧时的两倍以上；（2）与常氧相比，运动肌肉的静脉-动脉（v-a）[HLa]差异显著更大；（3）非运动肌肉的v-a[HLa]差异在常氧时略为负值，在低氧时更明显。这些研究表明，运动肌肉的氧供应减少会导致乳酸生成增加。
