Avtor/Urednik		Sketelj, J
Naslov		Neural regulation of acetylcholinesterase in skeletal muscles
Tip		članek
Vir		Basic Appl Myol
Vol. in št.		Letnik 4, št. 3
Leto izdaje		1994
Obseg		str. 281-91
Jezik		eng
Abstrakt		Acetylcholinesterase (AChE) is one of the key functional proteins of the neuromuscular junction (nmj). Although present throughout the muscle fibers, AChE is highly concentrated in the nmj, especially its asymmetric molecular forms. In the rat muscle, these forms are also produced extrajunctionally early in development but become restricted to the nmj during the first month after birth. Extrajunctional suppression of these forms is complete and irreversible in fast muscles whereas it is incomplete and reversible in the slow ones. Putative nerve released factors, adhesion processes and muscle activity act in concert to achieve development of nmj spontaneously active also in noninnervated immutare muscles, are usually activated together but may be triggered also independently. Fast and slow muscles differ in regard to AChE regulation. These differences are determined by intrinsic, muscle type specific mechanisms, and by extrinsic regulatory influences of different neural stimulation patterns in both muscles. Muscle activity maintains high level of AChE mRNA expression and, therefore, high AChE activity in the extrajunctional region of fast rat muscles, which is exactly opposite to regulation of acetylcholine receptor mRNA in these muslec. AChE activity in muscles of some other species (rabbit, chicken) is regulated in a completely different way. Ionic fluxes and especially the internal Ca2+ level seem to be important in coupling electromechanical activity with AchE regulation in muscle fibers.
Deskriptorji		MUSCLE, SKELETAL ACETYLCHOLINESTERASE NEUROMUSCULAR JUNCTION RABBITS RATS MUSCLE DENERVATION MUSCLE FIBERS