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Force impairment in calpain 3–deficient mice is not correlated with mechanical disruption
Author(s) -
Fougerousse Françoise,
Gonin Patrick,
Durand Muriel,
Richard Isabelle,
Raymackers JeanMarc
Publication year - 2003
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.10368
Subject(s) - calpain , muscular dystrophy , limb girdle muscular dystrophy , atrophy , muscle atrophy , dystrophy , medicine , endocrinology , anatomy , biology , pathology , mutation , gene , genetics , biochemistry , enzyme
Defects in human calpain 3 are responsible for limb‐girdle muscular dystrophy type 2A, an autosomal‐recessive disorder characterized mainly by late‐onset proximal muscular atrophy. A corresponding murine model has previously been generated by gene targeting. In this report, muscular activity of calpain 3–deficient (capn3 −/− ) mice was evaluated at different ages. Growth curves showed a progressive global muscular atrophy. Histological examination throughout the lifespan of mice confirmed the dystrophic lesions. Whole animal tests showed only a mild significant impairment of the forelimbs. Studies of the mechanical properties of selected isolated fast‐ and slow‐twitch muscles demonstrated that slow‐twitch muscles were significantly weaker in capn3 −/− mice than in wild‐type mice. Three different tests showed that there was no membrane disruption, suggesting a nonmechanical etiology of capn3 −/− mice dystrophy. These findings are consistent with a mechanism involving signaling systems. Muscle Nerve 27: 616–623, 2003