The Effects of Exercise-induced Fatigue on Acetylcholinesterase Expression and Activity at Rat Neuromuscular Junctions

© 2009 Acetylcholinesterase The Japan Society of is Histochemistry the enzyme and that Cy- terminates neurotransmission by hydrolyzing the acetylcholine released by the motoneurons at the neuromuscular junctions. Although acetylcholinesterase has been studied for almost a century, the underlying relationship between exercise-induced fatigue and acetylcholinesterase activity at the synaptic cleft is not clear. The purpose of this study was to assess the effects of exercise-induced fatigue on the expression and activity of acetylcholinesterase at the neuromuscular junctions. The expression and activity of acetylcholinesterase at the gastrocnemius neuromuscular junctions was decreased transiently by exercise-induced fatigue and then gradually increased over 24 hr. The expression of acetylcholinesterase in the 24 hr recovery group returned to the level of the control (non-exercised) group, but the activity of acetylcholinesterase remained significantly lower. These data suggest that the decrease of acetylcholinesterase expression and activity may be involved in the production and/or maintenance of exercise-induced fatigue.