Acetylcholinesterase content in both motor nerve and muscle is correlated with twitch properties

The activity and molecular forms of acetylcholinesterase (AChE) were studied in the rat soleus muscle and its nerve, as compared to their fast-twitch counterparts. The soleus muscle and its nerve exhibited both significantly lower AChE activity and less of the G4 (10S) molecular form. In addition, the soleus muscle displayed a specific increase in the A8 (13S) and A4 (8.8S) asymmetric forms, not seen in any of the fast-twitch muscles examined. These results indicate that the AChE content of a muscle and its nerve are linked and depend on the twitch properties, and that the slow-twitch muscle is characterized by a specific set of AChE molecular forms.