Author/Editor		Črne, N; Sketelj, J; Brzin, M
Title		Influence of innervation on molecular forms of acetylcholinesterase in regenerating fast and slow skeletal muscles
Type		članek
Source		J Neurosci Res
Vol. and No.		Letnik 28, št. 3
Publication year		1991
Volume		str. 315-23
Language		eng
Abstract		Nerve-intact musele regenerates were prepared by ischemic-toxic injury of slow soleus (SOL) and fast extensor digitorum longus (EDL) museles of the rat. Rapid innervation of regenerating myotubes modifed intrinsic patterns of AChE molecular forms, revealed by velocity sedimentation in linear sucrose gradients. Regarding their onset, the effects of innervation can be classified as early and late. The earliest changes in the SOL regenerates appeared a few days after innervation by their motoneurons: the activity of the 13 S AChE form (A 8) inereased signiticantly in comparison to non-innervated regenerates. The pattern of AChE molecular forms became similar to that in the normal SOL musele during the 2nd week after injury. In contrast, no major differences were observed hetween 8 day-old innervated and non-innervated EDL regenerates. Their patterns of AChE molecular forms resembled that in the normal EDL. However, the predominanee of the 10 S AChE form (G 4) characteristic for the 2-week old non-innervated regenerates was prevented by innervation. Early effect of innervation observed in the SOL regenerates but not in the EDL may be due to intrinsically different response of the regenerating SOL myotubes to innervation. Rather high extrajunetional activity of the asymmetric 16 S (A 12) molecular form of AChE in early regenerates was reduced to adult level in about 3 weeks in the SOL, and nearly completely suppressed in 5 weeks after innervation in the EDL regenerates. This reduction is assumed to be a late effect of innervation, as well as a decrease of the activity of the 4 S AChE form (G 1) in the SOL regenerates. A suppressive mechanism is activated in the extrajunetional regions of the innervated musele regenerates during their maturation. This mechanism counteracts the enhancing inÐuence of contractile activity on the expression of the asymmetric AChE forms in immature musele cells, and is more efficient in the EDL than in the SOL.(trunc.)
Descriptors		ACETYLCHOLINESTERASE ISOENZYMES MOTOR NEURONS MUSCLE PROTEINS MUSCLES MUSCLE CONTRACTION MUSCLES RATS, INBRED STRAINS REGENERATION