ISSN:
1432-0878
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Summary Denervated musculi gastrocnemii and solei of adult rats and rabbits were studied by weight analysis and by light and electron microscopy. The weight loss was severe and indicative of degenerative atrophy. Microscopic examinations showed no difference between the changes of nuclei in the gastrocnemius as compared with the soleus or between these muscles whether they were from rats or rabbits. Mitoses were found neither in normal nor in denervated muscle fibers, not even in animals which were killed at 3 o'clock in the morning or injected with colcemid at appropriate periods before death. Electron microscopic studies showed the earliest changes in the nuclei of denervated muscle to appear four hours after denervation. They involved aggregation of chromatin granules, loosening of nucleolar substance and uneven density of the nuclear membrane. They became very pronounced one to five days after denervation. Between the first week and the third month of denervation atrophy, infoldings and constrictions of muscle nuclei were conspicuous. From the fourth to fifth month, additional changes were the partitioning of muscle nuclei and the condensation of nuclear fragments and of nucleoli. Our findings gave no indication of mitoses to account for nuclear proliferation. Numerous and deep infoldings seen under the electron microscope indicated processes of nuclear partition which might produce viable nuclei, or nuclei subject to pyknosis, or might lead to ultimate disintegration of the fragments.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00339668
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