Factors Influencing Acetylcholinesterase Regulation in Slow and Fast Skeletal Muscles

Acetylcholinesterase (AChE) is an indispensable functional component of the neuromuscular junction. Therefore, it is highly concentrated at this small fraction of the sarcolemma (Marnay and Nachmansohn, 1938; Brzin and Zajicek, 1958). After revealing the molecular polymorphism of AChE, it was shown that it is mostly the Al2 asymmetric AChE form that is concentrated in the motor endplates (Hall, 1973). There is significant activity of other AChE forms extrajunctionally although their precise function, if any, is unknown. The asymmetric AChE forms are not specific for the neuromuscular junction, but become restricted to the endplates during muscle development (Sketelj and Brzin, 1980).