Fernandez H L, Donoso J A
Neuroscience Research laboratory, Veterans Administration Medical Center, Kansas City, Missouri 64128.
J Appl Physiol (1985). 1988 Nov;65(5):2245-52. doi: 10.1152/jappl.1988.65.5.2245.
Acetylcholinesterase (AChe) molecular forms were studied in hindlimb skeletal muscles from adult male Fischer 344 rats subjected to treadmill exercise for periods ranging between 1 and 30 days. Groups of three animals were exercised for 1 h/day at a treadmill speed of 8.5 m/min, with 1-min sprints at 15 m/min every 10 min. This exercise protocol led to a significant increase in the activity of G4 AChe in fast-twitch (gracilis and tibialis) but not in slow-twitch (soleus) muscles. Other AChe forms and muscle protein content remained unaltered. Such a selective enzymatic change was detected after a single exercise session, became more apparent after three daily sessions, and persisted for at least 30 days of exercise. A larger increment in G4 AChe activity was observed in gracilis muscle end-plate vs. non-end-plate regions. These findings show a specific adaptive reaction of fast-twitch muscles to enhanced motor activity, suggest that individual AChe forms in motor end plates are regulated through separate mechanisms, and support the hypothesis that membrane-bound G4 AChe plays an essential role in neuro-muscular transmission.
对成年雄性Fischer 344大鼠后肢骨骼肌中的乙酰胆碱酯酶（AChe）分子形式进行了研究，这些大鼠进行了1至30天不等的跑步机运动。每组三只动物，以8.5米/分钟的跑步机速度每天运动1小时，每10分钟以15米/分钟的速度进行1分钟冲刺。这种运动方案导致快肌（股薄肌和胫骨前肌）中G4 AChe的活性显著增加，而慢肌（比目鱼肌）中则没有。其他AChe形式和肌肉蛋白含量保持不变。单次运动后即可检测到这种选择性酶变化，每日三次运动后变得更加明显，并在至少30天的运动中持续存在。与非终板区域相比，在股薄肌终板中观察到G4 AChe活性有更大的增加。这些发现表明快肌对增强的运动活动有特定的适应性反应，表明运动终板中的各个AChe形式是通过不同的机制调节的，并支持膜结合G4 AChe在神经肌肉传递中起重要作用的假设。
