2000 Volume 71 Issue 1 Pages 63-70
The activity of membrane-bound acetylcholinesterase (AChE, EC 3. 1. 1. 7) in bovine muscle cells was enzyme-histochemically detailed in the M. longissimus thoracis during myogenesis in vivo and in vitro. AChE activity was detected in muscle satellite cells of regenerating muscles after an injection of the myotoxic agent, bupivacaine. In the myogenic cultures of satellite cells derived from regenerating muscles, AChE activity was found in mononucleated cells although they were a very low density, while all myotubes expressed AChE activity. The mononucleated cells positive for AChE activity (AChE+mononucleated cells) increased in number with an addition of insulin-like growth factor-I (IGF-I), but not with an addition of acidic fibroblast growth factor (aFGF) to the cultures. aFGF stimulated cell proliferation and IGF-I significantly induced the mononucleated cells positive for desmin, a muscle specific intermediate-filament protein (desmin+cells). The number of AChE+mononucleated cells and desmin+cells similarly changed in the myogenic cultures with IGF-I. The results support that AChE activity is expressed in postmitotic myoblasts which have been triggered to commit to the differentiation.
