Sveistrup H, Chan R Y, Jasmin B J
Department of Physiology, Faculty of Medicine, University of Ottawa, Ontario, Canada.
Am J Physiol. 1995 Oct;269(4 Pt 1):C856-62. doi: 10.1152/ajpcell.1995.269.4.C856.
We determined levels of mRNA encoding acetylcholinesterase (AChE) in muscles of rats subjected to chronic enhancement of neuromuscular activation. After 8 wk of voluntary wheel running, extensor digitorum longus (EDL) muscles displayed a 72% increase in total AChE activity as a result of a selective threefold increase in the G4 content. Soleus muscles, on the other hand, exhibited a 30% decrease in A12 while displaying a small (33%) increase in total AChE activity. These enzymatic adaptations were paralleled by increases in the levels of AChE mRNAs in both EDL (32%; P < 0.03) and soleus (42%; P < 0.02) muscles. In addition, compensatory hypertrophy of the plantaris muscle increased total AChE activity by 75%. This change was reflected by an elevation in all AChE molecular forms with A12 (89%) and A8 (179%) showing the most prominent increases. Similar to exercise-trained muscles, hypertrophied plantaris muscles displayed an increase in AChE transcripts (25%; P < 0.04). These results indicate that increases in neuromuscular activity modulate expression of the AChE gene in vivo and suggest the involvement of pretranslational regulatory mechanisms in the adaptive response of AChE to enhanced neuromuscular activation.
我们测定了慢性增强神经肌肉激活的大鼠肌肉中编码乙酰胆碱酯酶（AChE）的mRNA水平。在进行8周的自愿轮转跑步后，由于G4含量选择性地增加了三倍，趾长伸肌（EDL）的总AChE活性增加了72%。另一方面，比目鱼肌的A12减少了30%，而总AChE活性有小幅（33%）增加。这些酶适应性变化与EDL肌（32%；P < 0.03）和比目鱼肌（42%；P < 0.02）中AChE mRNA水平的增加相平行。此外，跖肌的代偿性肥大使总AChE活性增加了75%。这种变化反映在所有AChE分子形式的升高上，其中A12（89%）和A8（179%）的增加最为显著。与运动训练的肌肉相似，肥大的跖肌中AChE转录本增加（25%；P < 0.04）。这些结果表明，神经肌肉活动的增加在体内调节AChE基因的表达，并提示翻译前调节机制参与了AChE对增强的神经肌肉激活的适应性反应。
