Quantitation of muscle mass and muscle protein synthesis rate: documenting a response to myoblast transfer.

Initial trials of myoblast transfer into individual muscles should include studies of regional muscle mass. Magnetic resonance imaging is a safe and accurate technique that should be studied in the context of these trials. Creatinine excretion should also be measured in order to provide baseline information for future studies of myoblast injections into a larger number of muscles. In vivo assessment of muscle protein synthesis can be combined with histologic study to determine if the treatment alters the rate of protein synthesis.