The Study on the Characteristics of Myonuclei in Soleus Muscle Fibers Following Disuse Atrophy and Recover

The effects on the characteristics of myonuclei in soleus muscle fibers following 2 weeks disuse atrophy and 2 weeks recover were analysis. Immediately after removal, the left soleus muscle was cleaned of excess fat and connective tissues and weighed, entire single muscle fibers, sampled from tendon to tendon, was isolated with the use of fine needles. The muscle fibers were stained by propidium iodide (PI). Then, muscle fiber length, cross-sectional area (CSA), number and maximum CSA of the myonuclei, DNA concentration in each myonucleus and the number of sarcomere were measured using a confocal. The results indicated: In the present study, fiber atrophy was closely associated with a decrease in the number of myonuclei. The amount of fiber atrophy was greater than the loss of Myonuclei. The DNA concentration in a myonucleus was lower in the muscle fibers of disuse atrophy than control rats and this may impact nuclear function. May result is an imbalance between protein synthesis and degradation.