Myofibrillar differences among mammalian skeletal muscle fibres at the ultrastructural level. A comparison of immunocytochemical and morphometrical parameters
te Kronnie, G.; Pool, C.W.; Scholten, G.; van Raamsdonk, W.
European Journal of Cell Biology 22(2): 772-779
1980
ISSN/ISBN: 0171-9335 PMID: 7004873 Document Number: 157626
In the light microscope, 2 types (I, II) of soleus and M. plantaris of adult mice were discriminated using ultracryosections with immuno-ferritin and antisera against myosin isozymes. Muscle fibers of the M. plantaris are identified as type II fibers and the fibers of the M. soleus are divided in type I and type II fibers. In the immunologically identified fibers, the filament overlap in the Z-line was measured. The type II fibers of the M. plantaris have narrow Z-lines, whereas type I and type II fibers of the M. soleus have wide Z-lines. A classification of fibers based on Z-line width differs from the type I/type II classification. The antimyosin antibodies react exclusively with the A-band. In serial sections, the myosin isozymes can be identified unambiguously. This is a prerequisit for further studies of myosin isozyme distribution in mixed muscle fibers.