摘要
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 rats the mean density of square arrays (6 nm particles organized in orthogonal arrays) was 9.02/μm2 for the nonjunctional sarcolemmas of fast-twitch extensor digitorum longus (control EDL,CE) nuscle fibres and 0.34/μm2 for the nonjunctional 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 merves respectively for three months, the mean density was 0.45/μm2 for the nonjunetional sarcolemmas of the operated-EDL (OE) and 8.3/μm2 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.