Effect of denervation on rat soleus muscle: light morphometric and electron microscopic study

ABSTRACT

This study described the light, morphometric and ultrastructure of denervated rat soleus muscle, with a particular emphasis on understanding the ultrastructural changes and cellular basis for the reduced restorative capacity of denervated muscle. The right hind limbs of adult male Wister rats were denervated for periods of one, two, three and four weeks and the samples were processed for light and electron microscopy. Atrophy of muscle fibers was prominent from the first week. At further periods of denervation, atrophy of all muscle fibers was seen most clear with morphometry. As denervation progressed, the morphology of individual muscle fibers varied. Most of muscle fibers contained well-organized myofilaments; whereas in others, local areas of sarcomeric disorganization were evident. Mitochondria became smaller and rounded, the elements of the sarcoplasmic reticulum proliferated and became more disorganized, the autophagic vesicles were well present in the cytoplasm of atrophic muscle fibers. The satellite cells did not show signs of activation at four weeks after denervation