L. Bernheim et al., ROLE OF NICOTINIC ACETYLCHOLINE-RECEPTORS AT THE VERTEBRATE MYOTENDINOUS JUNCTION - A HYPOTHESIS, Neuromuscular disorders, 6(3), 1996, pp. 211-214
It has long been known that nicotinic acetycholine receptors (nAChRs)
are present in muscle fibres nor only at the end plate region but also
at the myotendinous junction (MTJ). Their function at the MTJ, howeve
r, is yet unknown, Recent experiments in our laboratory lead us to sug
gest that nAChRs at this site might be involved in muscle repair. MTJ
is subject to high mechanical stress and therefore is easily damaged.
We found in pure cultures of human myogenic cells that (1) the density
of nAChRs in myoblasts increases markedly just before cell fusion, (2
) the fusion of human myoblasts is accelerated by the presence of a ch
olinergic agonist acting on nAChRs and (3) human myoblasts and myotube
s spontaneously release an ACh-like compound, Based on these observati
ons we propose that in damaged muscles the nAChRs at the MTJ and those
of myogenic cells are activated by the ACh-like compound these cells
release. This leads to fusion of myogenic cells with damaged muscle fi
bres and hence promotes repair. Copyright (C) 1996 Elsevier Science Lt
d.