Changes of macromolecular organizations in nonjunctional sarcolemmas after cross—innervation—a study of fast—and slow—twitch muscle fiberes in rats

The purpose of the present study was to analyse the changes of macromolecular organizations in nonjunctional sarcolemmas of different types of skeletal muscle fibres after cross-innervation.In normal rate the mean density of square arrays(6nm particles organized in orthogonal of square arrays(6nm particles organized in othogonal arrays)was 9.02/μm^2 for the nonjunctional sarcolemmas of fast-twitch extensor digitorum longus(control EDL,CE)muscle fibres and 0.34/μm^2 for the nunjunctional sarcolemmas of slow-twitch soleus(control SOL,CS)muscle fibres.After cross-innervation between the fast-twitch EDL and slow-twitch SOL muscle fibres by slow and fast muscle nerves respectively for three months ,the mean density was 0.45/μm^2 for the nonjunctional sarcolemmas of the operated EDL(OE)and 8.3/μm^2 for the nonjunctional sarcolemmas of the operated SOL(OS).This indicates that the cross-innervation causes a reciprocal transformation of the number and distribution of such macromolecular organizations in the electrically excitable nonjunctional sarcolemmas.