Esser K A, White T P
Department of Kinesiology, University of Michigan, Ann Arbor 48109-2214.
J Appl Physiol (1985). 1990 Aug;69(2):451-5. doi: 10.1152/jappl.1990.69.2.451.
Run training can increase the mass of soleus muscle grafts, yet values remain lower than nongrafted muscle even with continued training. Thus we tested the hypothesis that nerve-implant soleus grafts of rats previously run trained would be refractory to the hypertrophic stimulus of ablation of synergistic muscle. We also compared the magnitude of growth of the nerve-implant soleus graft after ablation with that reported by others for the nerve-intact soleus graft. We studied eight groups that differed relative to the combination and order of treatments (running and ablation of synergistic muscle) and the graft age at the time of the ablation operation and study. Graft mass, protein concentration, and histochemical fiber composition were measured. Compared with grafts from cage-sedentary rats, the mass and protein content of the nerve-implant soleus grafts were higher (16-63%) at all times after ablation. When the ablation operation was performed at 56 days postgrafting, there was a 33% increase in protein content of the soleus graft by 84 days for cage-sedentary animals. This increase was twofold greater (P less than or equal to 0.02) than the 15% increase that followed ablation for the grafts from the animals that had been run trained before the ablation operation. Four weeks of run training before the ablation operation impaired the adaptive response of muscle grafts to the ablation of synergistic muscles, which may reflect alterations in motor unit recruitment and/or satellite cell activity. Ablation of synergistic muscles resulted in an absolute growth of the nerve-implant soleus grafts that was comparable with that reported for nerve-intact soleus grafts.
跑步训练可增加比目鱼肌移植物的质量，然而即便持续训练，其数值仍低于未移植的肌肉。因此，我们检验了这样一个假设：先前经过跑步训练的大鼠，其神经植入的比目鱼肌移植物对于协同肌切除所产生的肥大刺激将不敏感。我们还比较了协同肌切除后神经植入比目鱼肌移植物的生长幅度与其他人所报道的神经完整比目鱼肌移植物的生长幅度。我们研究了八组大鼠，它们在治疗组合及顺序（跑步训练和协同肌切除）以及切除手术和研究时移植物的年龄方面存在差异。测量了移植物质量、蛋白质浓度和组织化学纤维组成。与笼养久坐大鼠的移植物相比，协同肌切除后任何时候，神经植入比目鱼肌移植物的质量和蛋白质含量都更高（高出16 - 63%）。当在移植后56天进行切除手术时，笼养久坐动物的比目鱼肌移植物蛋白质含量在84天时增加了33%。这一增加幅度比切除手术前经过跑步训练的动物的移植物在切除后15%的增加幅度高出两倍（P≤0.02）。切除手术前四周的跑步训练损害了肌肉移植物对协同肌切除的适应性反应，这可能反映了运动单位募集和/或卫星细胞活性的改变。协同肌切除导致神经植入比目鱼肌移植物的绝对生长，这与报道的神经完整比目鱼肌移植物的生长情况相当。
