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Calmodulin content and Ca‐activated protease activity in dystrophic hamster muscles
Author(s) -
Klamut Henry J.,
Lin Chao Hsiung,
Strickland Kenneth P.
Publication year - 1983
Publication title -
muscle and nerve
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.025
H-Index - 145
eISSN - 1097-4598
pISSN - 0148-639X
DOI - 10.1002/mus.880060607
Subject(s) - calmodulin , skeletal muscle , medicine , endocrinology , myofibril , hamster , muscular dystrophy , biology , tongue , chinese hamster , chemistry , anatomy , biochemistry , calcium , pathology , dna
Abstract As part of a study on the implication of elevated Ca 2+ levels in the myofibrillar degeneration seen in dystrophic muscle, the content of calmodulin and the activity of Ca 2+ ‐activated neutral protease (CANP) have been measured in normal and dystrophic (UM‐X7.1) hamsters. Calmodulin levels, expressed as micrograms ± SEM per gram wet weight were highest in brain (385 ± 24.7), followed by tongue (93.88 ± 3.93), heart (42.13 ± 2.93), and skeletal muscle (31.69 ± 1.42). No significant increases in calmodulin were observed in the dystrophic tissues thus suggesting that the Ca 2+ accumulations observed in dystrophic muscles are unrelated to changes in calmodulin levels. Because of the complexity of regulation of CANP, a time‐dependent study was done using extracts of skeletal, heart, and tongue muscles. Marginal increases in dystrophic CANP were seen in skeletal muscle at all times studied and in the heart and tongue at initial time points only. The data are discussed in terms of rising levels of Ca 2+ in muscles of the UM‐X7.1 hamster being sufficient to increase CANP activity (without increasing content) to where it causes Z‐line dissolution.