Ultrastructural changes and glutathione depletion in the skeletal muscle induced by protein malnutrition.
Ultrastructural changes and glutathione level were investigated in the pectoralis muscle of rats fed a low-protein diet. Electron microscopy demonstrated the ultrastructural changes of occasional myofibrils affected with protein deficiency that were characterized with the streaming and/or disruption of the Z-line and disintegration of sarcomeric striation. In the affected sarcomeres, sarcomere length was often elongated and fragmented thick filaments were present together with dense amorphous materials flowing from the damaged Z-line. Glutathione level of muscle in the low-protein diet group (5% casein) was reduced to about one-third of that in the control diet group (20% casein). The study suggests that depletion of glutathione by protein malnutrition is responsible for inducing myofibrillar damage through the excess leaking of Ca2+ into the cytosol.
Oumi
M
M
Department of Anatomy and Nutrition Morphology, Graduate School of Health and Nutrition Sciences, Nakamura Gakuen University, Fukuoka, Japan. oumi@cc.nakamura-u.ac.jp
Miyoshi
M
M
Yamamoto
T
T
D000818:Animals; D018753:Diet, Protein-Restricted; D005978:Glutathione / Q000172:deficiency*; D010369:Pectoralis Muscles / Q000378:metabolism* / Q000648:ultrastructure*; D011502:Protein-Energy Malnutrition / Q000378:metabolism*; D051381:Rats; D012518:Sarcomeres / Q000648:ultrastructure
D005978:Glutathione