Effects of live high, train low hypoxic exposure on lactate metabolism in trained humans
Effects of live high, train low hypoxic exposure on lactate metabolism in trained humans
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DOI：
10.1152/japplphysiol.00799.2003
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发表时间：
2004-02-01
影响因子：
3.3
通讯作者：
Hawley, JA
中科院分区：
文献类型：
--
作者：
Clark, SA;Aughey, RJ;Hawley, JA
我们对29名训练有素的自行车运动员和铁人三项运动员进行了20晚高氧低氧（LHTL）暴露对乳酸动力学、单羧酸乳酸转运蛋白（MCT1和MCT4）和肌肉体外缓冲能力（betam）的影响。受试者被分为三组：连续20晚低氧暴露组（LHTLc）， 20晚间歇性低氧暴露组（4个5晚的缺氧区，每个缺氧区穿插2晚的正常缺氧区（LHTLi）），或对照组（Con）。乳酸出现率（R-a）、消失率（R-d）和氧化率（R-ox）是通过在90分钟的稳态运动中连续输注L-[U-C-14]乳酸示踪剂来测定的[60分钟以65%的峰值摄取O-2 (（V)比dot O-2（峰值）），然后30分钟以85% (V)比dot O-2（峰值）]。在LHTL治疗20晚之前和之后分别进行静息肌肉活检，以测定β、MCT1和MCT4蛋白的丰度。运动前60分钟的R-a在两组之间没有差异。在最后25 min运动时，R-a高于运动时的峰值(V)比O-2点高85% (P < 0.05)，而在LHTLc中R-a低于其他组（P < 0.05）。R-d和R-a的模式相似。虽然在运动期间R-ox显著增加了85%，而(V)比dot O-2（峰值）增加了65%，但三组之间或试验之间没有差异。低氧暴露对βm或MCT1和MCT4蛋白丰度没有影响。我们的结论是，在训练有素的运动员进行高强度运动时，连续20个晚上的缺氧暴露会降低全身R-a。然而，乳酸代谢和pH调节的肌肉标志物在LHTL干预下没有改变。
We determined the effect of 20 nights of live high, train low (LHTL) hypoxic exposure on lactate kinetics, monocarboxylate lactate transporter proteins (MCT1 and MCT4), and muscle in vitro buffering capacity (betam) in 29 well-trained cyclists and triathletes. Subjects were divided into one of three groups: 20 consecutive nights of hypoxic exposure (LHTLc), 20 nights of intermittent hypoxic exposure [ four 5-night blocks of hypoxia, each interspersed with 2 nights of normoxia (LHTLi)], or control ( Con). Rates of lactate appearance (R-a), disappearance (R-d), and oxidation (R-ox) were determined from a primed, continuous infusion of L-[U-C-14] lactic acid tracer during 90 min of steady-state exercise [60 min at 65% peak O-2 uptake ((V) over dot O-2 (peak)) followed by 30 min at 85% (V) over dot O-2 (peak)]. A resting muscle biopsy was taken before and after 20 nights of LHTL for the determination of betam and MCT1 and MCT4 protein abundance. R-a during the first 60 min of exercise was not different between groups. During the last 25 min of exercise at 85% (V) over dot O-2 (peak), R-a was higher compared with exercise at 65% of (V) over dot O-2 peak and was decreased in LHTLc (P < 0.05) compared with the other groups. R-d followed a similar pattern to R-a. Although R-ox was significantly increased during exercise at 85% compared with 65% of (V) over dot O-2 (peak), there were no differences between the three groups or across trials. There was no effect of hypoxic exposure on βm or MCT1 and MCT4 protein abundance. We conclude that 20 consecutive nights of hypoxia exposure decreased whole body R-a during intense exercise in well-trained athletes. However, muscle markers of lactate metabolism and pH regulation were unchanged by the LHTL intervention.