Ultrastructural Changes of Muscular Dystrophy

Keimyung Medical Journal 1985;4(2):143-150.

근이영양증 근세포의 미세형태학적 변화

김덕영; 손태중

Abstract

The author studied two cases of Duchenne type of muscular dystrophy by light and electron microscope to examine the morphologic interpretation about morphologic change and pathogenesis of them. The results obtained were as follow: Light microscopically，decrease of muscle fibers, increase of connective tissue, irregularity and rarefaction of muscle of muscle fibers, hyaline degeneration were observed. Histologic findings were markedly variable from nearly normal to markedly affected foci showing severe destruction of muscle fibers and muscle fibers and stromal fatty infiltration. Electron microscopically, there were focal loss of myofibrils around Z-line which is replaced by mitochondria, dilated SR and lipid droplets on the minimally affected foci. But severely affected portion shows widespread fragmentation of muscle fibers and focal rarefaction of muscle fibers. Rarefaction was especially prominent just beneath sarcolemma. Rarefacted area which composed of granular substance and degenerated membranous tissue was especially prominent just beneath sarcolemma. Considering the variable rarefaction of muscle fibers which is more prominent beneath degenerated sarcolemma, degeneration of sarcolemma was supposed to be involved on the pathogenesis of muscular dystrophy. And it is reasonable to interpret clinical findings of various muscular dystrophy according to the theory about degeiieration of sarcolemma. But this study is indirect one and requires further studies about abnomalities of sarcolemma by direct method.