Pearson J K, Sickles D W
Department of Anatomy, Medical College of Georgia, Augusta 30912.
J Appl Physiol (1985). 1987 Dec;63(6):2301-8. doi: 10.1152/jappl.1987.63.6.2301.
Quantitative enzyme histochemical methods have been used to determine the effect of ablation of synergists on the oxidative metabolism of the alpha-motoneurons and muscle fibers of the rat soleus. Sixty days postablation, the NADH-tetrazolium reductase (NADH-TR) activity of soleus motoneurons decreased 12.5% from 0.327 +/- 0.005 (mean +/- SE; optical density units) to 0.286 +/- 0.007. In the muscle fibers, the alpha-glycerophosphate dehydrogenase activity (glycolytic enzyme) decreased from 0.114 +/- 0.010 to 0.074 +/- 0.009, a change of 35.1%, and the NADH-TR activity decreased 21.2% from 0.348 +/- 0.018 to 0.274 +/- 0.017. In both the motoneurons and the muscle fibers, the decrease was nonspecific for all cells, although a greater effect on the cells with higher enzyme activity was observed. The decreased NADH-TR activity represents a shift in the oxidative profile of the motoneurons and muscle fibers, indicating a decreased ability to use oxidative metabolism for periods of short-term high-energy demands. Furthermore, the parallel decrease in muscle fibers and motoneurons with high NADH-TR activity (fast-twitch oxidative-glycolytic fibers and presumably also motoneurons) demonstrates the tight correlation of the NADH-TR activity between these parts of the motor unit in both control and synergist-ablated muscles.
定量酶组织化学方法已被用于确定切除协同肌对大鼠比目鱼肌α运动神经元和肌纤维氧化代谢的影响。切除术后60天，比目鱼肌运动神经元的NADH-四唑还原酶（NADH-TR）活性从0.327±0.005（平均值±标准误；光密度单位）降至0.286±0.007，下降了12.5%。在肌纤维中，α-甘油磷酸脱氢酶活性（糖酵解酶）从0.114±0.010降至0.074±0.009，变化了35.1%，NADH-TR活性从0.348±0.018降至0.274±0.017，下降了21.2%。在运动神经元和肌纤维中，所有细胞的下降都是非特异性的，尽管观察到对酶活性较高的细胞影响更大。NADH-TR活性的降低代表了运动神经元和肌纤维氧化特征的转变，表明在短期高能量需求期间利用氧化代谢的能力下降。此外，具有高NADH-TR活性的肌纤维和运动神经元（快肌氧化糖酵解纤维以及可能还有运动神经元）平行下降，这表明在对照肌肉和切除协同肌的肌肉中，运动单位这些部分之间的NADH-TR活性紧密相关。
