Implantation of normal muscle precursor cells (mpc) for treatment for
inherited myopathies such as Duchenne muscular dystrophy is in clear n
eed of improvement to become practicable, but few variables have been
studied comparatively. Here, we report the first quantitative estimate
of the effectiveness of implanting mpc into preirradiated muscles of
young and old mice and into preirradiated and nonirradiated old muscle
s. Estimates were made of the amount of muscle formed by injection of
5 x 10(5) cells dissociated from neonatal normal mouse muscle into tib
ialis anterior muscles of the dystrophin-deficient mdx mouse. We show
that normal mpc are incorporated slightly more efficiently into muscle
s of young than old host mice, to form some 10 mg of dystrophin-positi
ve fibers. In older muscles, prior irradiation has little effect on th
e total yield of new muscle. (C) 1996 John Wiley & Sons, Inc.