Loss and renewal of thick myofilaments in glucocorticoid-treated rat soleus after denervation and reinnervation
Version of Record online: 13 OCT 2004
Copyright © 1992 John Wiley & Sons, Inc.
Muscle & Nerve
Volume 15, Issue 11, pages 1290–1298, November 1992
How to Cite
Massa, R., Carpenter, S., Holland, P. and Karpati, G. (1992), Loss and renewal of thick myofilaments in glucocorticoid-treated rat soleus after denervation and reinnervation. Muscle Nerve, 15: 1290–1298. doi: 10.1002/mus.880151112
- Issue online: 13 OCT 2004
- Version of Record online: 13 OCT 2004
- Manuscript Accepted: 28 APR 1992
- thick myofilaments;
- rat soleus muscle;
Denervation of rat soleus muscle and simultaneous administration of high doses of corticosteroids for 7 days caused marked muscle fiber atrophy and selective loss of thick myofilaments from many muscle fibers by light and electron microscopy. Myosin heavy chain/ actin ratios were greatly reduced on polyacrylamide gel electrophoresis. Nerve crush instead of cut permitted reinnervation after 2 weeks and demonstrated the reversibility of the muscle changes within a week after reinnervation. There was formation of new thick filaments and their reintegration into myofibrils without further breakdown, although large areas of Z-disc streaming appeared. The mechanism of A-band breakdown remains obscure, but it presumably starts with limited proteolysis and continues with disaggregation of myosin molecules. This is consistent with our observation that the muscle fibers retain a relatively good reactivity to antibodies against myosin heavy chain 1 week after denervation and corticosteroid administration. A syndrome recalling these experiments is seen in severely asthmatic patients receiving corticosteroids and pharmacologically paralyzed for mechanical respiration. © 1992 John Wiley & Sons, Inc.