Green H J, Sutton J R, Wolfel E E, Reeves J T, Butterfield G E, Brooks G A
Department of Kinesiology, University of Waterloo, Ontario, Canada.
J Appl Physiol (1985). 1992 Dec;73(6):2701-8. doi: 10.1152/jappl.1992.73.6.2701.
To determine whether the working muscle is able to sustain ATP homeostasis during a hypoxic insult and the mechanisms associated with energy metabolic adaptations during the acclimatization process, seven male subjects [23 +/- 2 (SE) yr, 72.2 +/- 1.6 kg] were given a prolonged exercise challenge (45 min) at sea level (SL), within 4 h after ascent to an altitude of 4,300 m (acute hypoxia, AH), and after 3 wk of sustained residence at 4,300 m (chronic hypoxia, CH). The prolonged cycle test conducted at the same absolute intensity and representing 51 +/- 1% of SL maximal aerobic power (VO2 max) and between 64 +/- 2 (AH) and 66 +/- 1% (CH) at altitude was performed without a reduction in ATP concentration in the working vastus lateralis regardless of condition. Compared with rest, exercise performed during AH resulted in a greater increase (P < 0.05) in muscle lactate concentration (5.11 +/- 0.68 to 22.3 +/- 6.1 mmol/kg dry wt) than exercise performed either at SL (5.88 +/- 0.85 to 11.5 +/- 3.1) or CH (5.99 +/- 0.88 to 12.4 +/- 2.1). These differences in lactate concentration have been shown to reflect differences in arterial lactate concentration and glycolysis (Brooks et al. J. Appl. Physiol. 71: 333-341, 1991). The reduction in glycolysis at least between AH and CH appears to be accompanied by a tighter metabolic control. During CH, free ADP was lower and the ATP-to-free ADP ratio was increased (P < 0.05) compared with AH.(ABSTRACT TRUNCATED AT 250 WORDS)
为了确定工作肌肉在低氧损伤期间是否能够维持三磷酸腺苷（ATP）内稳态，以及在适应过程中与能量代谢适应相关的机制，对7名男性受试者[23±2（标准误）岁，72.2±1.6千克]进行了如下实验：在海平面（SL）进行长时间运动挑战（45分钟），在上升到4300米海拔高度后4小时内（急性低氧，AH），以及在4300米持续居住3周后（慢性低氧，CH）。在相同绝对强度下进行的长时间循环测试，代表海平面最大有氧功率（VO2 max）的51±1%，在海拔高度时代表急性低氧时的64±2%和慢性低氧时的66±1%，无论何种情况，工作的股外侧肌中的ATP浓度均未降低。与休息时相比，急性低氧期间进行的运动导致肌肉乳酸浓度（5.11±0.68至22.3±6.1毫摩尔/千克干重）的增加幅度大于在海平面（5.88±0.85至11.5±3.1）或慢性低氧（5.99±0.88至12.4±2.1）时进行的运动。乳酸浓度的这些差异已被证明反映了动脉乳酸浓度和糖酵解的差异（布鲁克斯等人，《应用生理学杂志》71：333 - 341，1991）。至少在急性低氧和慢性低氧之间，糖酵解的减少似乎伴随着更严格的代谢控制。与急性低氧相比，在慢性低氧期间，游离二磷酸腺苷（ADP）较低，ATP与游离ADP的比值增加（P<0.05）。（摘要截短至250字）
