Affiliations: [a] Center for Plastic-, Hand- and Reconstructive Surgery, University Hospital Regensburg, Germany
| [b] Institute of Pathology, University of Regensburg, Regensburg, Germany
| [c] Translational Molecular Pathology, University of Texas MD, Houston, TX, USA
Correspondence:
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Corresponding author: S. M. Klein, Center for Plastic-, Hand- and Reconstructive Surgery, University Hospital Regensburg, Germany. Tel.: +49 941 944 4890; Fax: +49 941 6948; E-mail: silvan.klein@ukr.de.
Abstract: BACKGROUND: Duchenne muscular dystrophy (DMD) consists of a lack in the expression of the subsarcolemmal protein dystrophin causing progressive muscle dysfunction. Among the widely applied animal models in DMD research is the C57BL/1010ScSn-Dmdmdx mouse, commonly referred to as the “mdx mouse”. The potential benefit of novel interventions in this model is often assessed by variables such as functional improvement, histological changes, and creatine kinase (CK) serum levels as an indicator for the extent of in situ muscle damage. OBJECTIVE: Our objective was to determine to what extent the serum CK-level serves a surrogate for muscle dysfunction. METHODS: In this trial mdx mice were subjected to a four-limb wire-hanging test (WHT) to assess the physical performance as a reference for muscle function. As CK is a component of the muscle fiber cytosol, its serum activity is supposed to positively correlate with progressing muscle damage. Hence serum CK levels were measured to detect the degree of muscle impairment. The functional tests and the serum CK levels were analyzed for their specific correlation. RESULTS: Although physical performance decreased during the course of the experiment, latency to fall times in the WHT did not correlate with the CK level in mdx mice. CONCLUSION: Our data suggests that the serum CK activity might be a critical parameter to monitor the progression of muscle impairment in mdx mice. Further this study emphasizes the complexity of the DMD phenotype in the mdx mouse, and the care with which isolated parameters in this model should be interpreted.
Keywords: Duchenne muscular dystrophy, mdx mouse, muscle impairment, CK level, diagnostic methods, serum biomarker for muscle imparment
