Pilegaard H, Juel C
Copehagen Muscle Research Centre, August Krogh Institute, University of Copenhagen, Denmark.
Am J Physiol. 1995 Oct;269(4 Pt 1):E679-82. doi: 10.1152/ajpendo.1995.269.4.E679.
The effect of denervation on lactate transport capacity was studied in giant sarcolemmal vesicles obtained from rat muscle. The rate of lactate transport was determined in soleus and red (RG) and white gastrocnemius (WG) after 1, 3, and 21 days of denervation and in the corresponding contralateral muscles. In addition, muscle lactate dehydrogenase (LDH) and succinate dehydrogenase (SDH) activities were determined. After 1, 3, and 21 days of denervation the rate of lactate transport was lower (P < 0.05) in WG (9, 11, and 36%), RG (15, 21, and 41%), and soleus (12, 24, and 50%) compared with the contralateral muscles. After 21 days of denervation LDH activity was 26, 25, and 34% and SDH activity 33, 25, and 27% lower (P < 0.05) in WG, RG, and soleus, respectively, compared with the contralateral muscles. In the control muscles the lactate transport capacity was 20 and 32% lower (P < 0.05) in WG than in RG and soleus, respectively. The present findings provide support that the sarcolemmal lactate carrier is a plastic system; the transport capacity in soleus, RG, and WG already declines after 1 day of denervation and is further reduced after 21 days of denervation. In addition, the data suggest that the lactate transport capacity in fast-twitch glycolytic fibers < fast-twitch oxidative-glycolytic fibers < slow-twitch oxidative fibers.
在从大鼠肌肉获取的巨大肌膜囊泡中研究了去神经支配对乳酸转运能力的影响。在去神经支配1天、3天和21天后，测定比目鱼肌、红色（RG）和白色腓肠肌（WG）及其相应对侧肌肉的乳酸转运速率。此外，还测定了肌肉乳酸脱氢酶（LDH）和琥珀酸脱氢酶（SDH）的活性。与对侧肌肉相比，去神经支配1天、3天和21天后，WG（分别降低9%、11%和36%）、RG（分别降低15%、21%和41%）和比目鱼肌（分别降低12%、24%和50%）的乳酸转运速率较低（P<0.05）。去神经支配21天后，与对侧肌肉相比，WG、RG和比目鱼肌的LDH活性分别降低26%、25%和34%，SDH活性分别降低33%、25%和27%（P<0.05）。在对照肌肉中，WG的乳酸转运能力分别比RG和比目鱼肌低20%和32%（P<0.05）。本研究结果支持肌膜乳酸载体是一个可塑性系统；去神经支配1天后，比目鱼肌、RG和WG中的转运能力就已经下降，去神经支配21天后进一步降低。此外，数据表明，快肌糖酵解纤维<快肌氧化糖酵解纤维<慢肌氧化纤维中的乳酸转运能力。
