Jóhannsson E, Waerhaug O, Bonen A
Norwegian University of Sport and Physical Education, Oslo, Norway.
Am J Physiol. 1996 Jun;270(6 Pt 2):R1355-60. doi: 10.1152/ajpregu.1996.270.6.R1355.
We determined whether the twitch-velocity phenotype or the metabolic phenotype of a muscle influences the content of GLUT-4 and GLUT-1 proteins. The soleus (Sol) and extensor digitorum longus (EDL) muscles were cross-reinnervated (X-Sol, X-EDL). After 3 mo the X-EDL had become enriched in slow-twitch oxidative (SO) fibers (70.5% SO) compared with its control (3.8% SO), whereas the X-Sol became enriched in fast-twitch oxidative-glycolytic (FOG) fibers (78.6% FOG) compared with its control (10% FOG). Thus the twitch phenotype of X-Sol shifted to fast-twitch muscle, whereas X-EDL shifted to a slow-twitch muscle. In the X-EDL, the oxidative nature of the X-EDL was increased to 97% oxidative fibers compared with 43% oxidative fibers in the normal EDL. In the Sol the oxidative nature of the X-Sol was retained at 100%. GLUT-4 content was increased 1.6-fold in the X-EDL (P < 0.05) but was not changed in the X-Sol (P > 0.05). GLUT-1 content was increased fourfold in X-EDL but was not altered in the X-Sol. We conclude that GLUT-4 and GLUT-1 content in muscle is related to the oxidative phenotype of the muscle rather than the twitch-velocity phenotype.
我们确定了肌肉的抽搐速度表型或代谢表型是否会影响GLUT - 4和GLUT - 1蛋白的含量。对比目鱼肌（Sol）和趾长伸肌（EDL）进行交叉神经支配（X - Sol，X - EDL）。3个月后，与对照相比，X - EDL富含慢肌氧化（SO）纤维（70.5% SO），而对照中SO纤维仅占3.8%；而与对照相比，X - Sol富含快肌氧化糖酵解（FOG）纤维（78.6% FOG），对照中FOG纤维占10%。因此，X - Sol的抽搐表型转变为快肌，而X - EDL转变为慢肌。在X - EDL中，其氧化性质的纤维增加到97%，而正常EDL中氧化纤维仅占43%。在比目鱼肌中，X - Sol的氧化性质保持在100%。X - EDL中GLUT - 4含量增加了1.6倍（P < 0.05），但X - Sol中未发生变化（P > 0.05）。X - EDL中GLUT - 1含量增加了四倍，但X - Sol中未改变。我们得出结论，肌肉中GLUT - 4和GLUT - 1的含量与肌肉的氧化表型有关，而非抽搐速度表型。
