Dynamics of nuclei of muscle fibers and connective tissue cells in normal and denervated rat muscles
Article first published online: 14 MAR 2000
Copyright © 2000 John Wiley & Sons, Inc.
Muscle & Nerve
Volume 23, Issue 4, pages 617–626, April 2000
How to Cite
Schmalbruch, H. and Lewis, D.M. (2000), Dynamics of nuclei of muscle fibers and connective tissue cells in normal and denervated rat muscles. Muscle Nerve, 23: 617–626. doi: 10.1002/(SICI)1097-4598(200004)23:4<617::AID-MUS22>3.0.CO;2-Y
- Issue published online: 14 MAR 2000
- Article first published online: 14 MAR 2000
- Manuscript Accepted: 16 NOV 1999
- Danish MRC and Action Research
- skeletal muscle
The mitotic activity in muscles of growing rats and the effect of denervation were studied by means of continuous infusion of 5-bromo-2-deoxyuridine (BRDU). Denervated muscles after 10 weeks contained 20 to 60% fewer muscle nuclei than normal; BRDU labeled about 25% of the nuclei of normal soleus and extensor digitorum longus (EDL) and of denervated EDL muscles but only 5% in the denervated soleus muscle. Labeled nuclei persisted in denervated but not in normal muscles. After the main growth period, the turnover of myonuclei was at most 1 to 2% per week. The behavior of connective tissue nuclei was similar to that in muscle fibers. Infusion of BRDU had no effect on contractile properties. It is suggested that the exceptionally rapid atrophy of the denervated rat soleus associated with loss of satellite cells was due to loss of myonuclei and differentiation and fusion of satellite cells. The cause may possibly be that the phase of postdenervation fibrillation is shorter than in other muscles. © 2000 John Wiley & Sons, Inc. Muscle Nerve 23: 617–626, 2000.