Monitoring Murine Skeletal Muscle Function for Muscle Gene Therapy
The primary function of skeletal muscle is to generate force. Muscle force production is compromised in various forms of acquired and/or inherited muscle diseases. An important goal of muscle gene therapy is to recover muscle strength. Genetically engineered mice and spontaneous mouse mutants are readily available for preclinical muscle gene therapy studies. In this chapter, we outlined the methods commonly used for measuring murine skeletal muscle function. These include ex vivo and in situ analysis of the contractile profile of a single intact limb muscle (the extensor digitorium longus for ex vivo assay and the tibialis anterior muscle for in situ assay), grip force analysis, and downhill treadmill exercise. Force measurement in a single muscle is extremely useful for pilot testing of new gene therapy protocols by local gene transfer. Grip force and treadmill assessments offer body-wide evaluation following systemic muscle gene therapy.
Key wordsSkeletal muscle Twitch force Tetanic force Eccentric contraction Grip strength Treadmill Gene therapy
The studies are supported by grants from the National Institutes of Health AR-49419 and the Muscular Dystrophy Association. We thank Drs. Rob Grange, Frank Booth, Steve Yang, and Ron Terjung for helpful discussion during the protocol development.
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