Acetylcholinesterase of the motor endplate and its response to muscle denervation.
In innervated and denervated sternohyoid muscles of adult mice the AChE with a pH optimum at 7.2 was shown to occur in all three fiber types in two separate structural areas located: extrafibrillarly (synaptic cleft, postsynaptic folds, subsarcolemmal vesicles, T-tubules, interfibrillar space) and intrafibrillarly (perinuclear cisternae, SR including SR cisternae). There is not a stable connection between the two areas. The functional significance of the intrafibrillar AChE, in particular, is unknown. After muscle denervation, intrafibrillar AChE of the A and B fibers disappears more quickly than that of C fibers. This phenomenon not only suggests a general, but possibly also a fiber-specific neurotrophic effect.
D000110:Acetylcholinesterase / Q000378:metabolism*; D000818:Animals; D006651:Histocytochemistry; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D008854:Microscopy, Electron; D009045:Motor Endplate / Q000201:enzymology* / Q000648:ultrastructure; D009121:Muscle Denervation; D009469:Neuromuscular Junction / Q000201:enzymology*
D000110:Acetylcholinesterase