Pilegaard H, Mohr T, Kjaer M, Juel C
Copenhagen Muscle Research Centre: LCMF, Bispebjerg Hospital, University of Copenhagen, Denmark.
Scand J Med Sci Sports. 1998 Apr;8(2):98-101. doi: 10.1111/j.1600-0838.1998.tb00175.x.
In order to evaluate the effect of prolonged muscle inactivity on sarcolemmal lactate/H+ transport in humans, the lactate/H+ transport capacity was determined in the thigh muscle of spinal-cord-injured (SCI) individuals. The lactate transport rate was measured in sarcolemmal giant vesicles produced by collagenase treatment of muscle biopsies obtained from the vastus lateralis muscle. Six SCI subjects with total loss of motor and sensory functions of their lower limbs participated in the study. The duration of the injury ranged from 2 to 15 years. The total lactate transport rate in the muscle of SCI patients was 46.5 +/- 2.6 pmol.cm-2.s-1 (mean +/- SEM), which corresponds to a 17% lower (P < 0.05) transport rate than that found in healthy, untrained subjects. The estimated carrier-mediated lactate/H+ transport capacity was approximately 26% lower in the SCI patients than in healthy, untrained subjects. The observed muscle lactate/H+ transport capacity of SCI individuals is in accordance with a positive correlation between the capacity of the lactate/H+ transporters and the percentage occurrence of slow-twitch fibres in a muscle, although there seems to be a wide range of transport capacities within each fibre type. The present results show that the sarcolemmal lactate/H+ transport capacity is lower in SCI individuals than in normally physically active subjects, which indicates that prolonged muscle inactivity reduces the lactate/H+ transport capacity of human muscle.
为了评估长时间肌肉不活动对人体肌膜乳酸/氢离子转运的影响，在脊髓损伤（SCI）个体的大腿肌肉中测定了乳酸/氢离子转运能力。通过对取自股外侧肌的肌肉活检组织进行胶原酶处理来制备肌膜巨囊泡，并测定其中的乳酸转运速率。六名下肢运动和感觉功能完全丧失的SCI受试者参与了该研究。损伤持续时间为2至15年。SCI患者肌肉中的总乳酸转运速率为46.5±2.6 pmol·cm⁻²·s⁻¹（平均值±标准误），与健康的未经训练的受试者相比，该转运速率低17%（P<0.05）。SCI患者中估计的载体介导的乳酸/氢离子转运能力比健康的未经训练的受试者低约26%。尽管在每种纤维类型中似乎存在广泛的转运能力范围，但观察到的SCI个体的肌肉乳酸/氢离子转运能力与肌肉中乳酸/氢离子转运体的能力和慢肌纤维的出现百分比之间呈正相关。目前的结果表明，SCI个体的肌膜乳酸/氢离子转运能力低于正常身体活动的受试者，这表明长时间的肌肉不活动会降低人体肌肉的乳酸/氢离子转运能力。
