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Muscle atrophy and restoration during molting

Conference ·
OSTI ID:6477962

The ultrastructural basis of atrophy of claw closer muscle of the land crab (Gecarcinus lateralis) and the organization of myofibrils and sarcoplasmic reticulum during the hydrolysis of protein that occurs during proecdysis were examined. Proecdysis was initiated by autotomy of seven or eight walking legs. In some ways, the ultrastructure of the accompanying claw muscle atrophy resembles that of other atrophies induced by denervation, disuse, and disease in that lysosomes do not appear to be involved in myofilament degradation. The changes that occur in contractile proteins during claw muscle atrophy and the involvement of Ca/sup 2 +/-dependent proteinase (CDP) in myofilament degradation were investigated. In contrast to other systems, there is a preferential degradation of thin filaments relative to thick filaments, resulting in an increase in thick-filament packing density. Crab CDP hydrolyzes several myofibrillar proteins including actin and myosin. Its activity is more than two-fold greater in proecdysial muscle, suggesting that the CDP plays a significant role in claw muscle atrophy. 68 references, 12 figures. (ACR)

Research Organization:
Oak Ridge National Lab., TN (USA)
DOE Contract Number:
AC05-84OR21400
OSTI ID:
6477962
Report Number(s):
CONF-821269-2-Draft; ON: DE85000961
Country of Publication:
United States
Language:
English