Potentiation of myoblast transplantation by host muscle irradiation is dependent on the rate of radiation delivery

Transplantation of muscle precursor cells (mpc) has been suggested as a tre atment for myopathies, such as Duchenne muscular dystrophy. Irradiation of skeletal muscle with 16-20 Gy prevents muscle regeneration and also augment s muscle formation from implanted muscle precursor cells (mpc). However, wh en mdx nu/nu mouse muscles are preirradiated at 0.73 Gy/min rather than at 1.29 Gy/min prior to their injection with normal mpc, significantly more mu scle fibres of donor origin are formed. This suggests that the rate at whic h irradiation is delivered has a physiological effect on the muscle. Althou gh it would not be feasible to irradiate a patient's muscles prior to mpc i mplantation, once the factor(s) which are altered in irradiated muscle have been identified, it might be possible to use these to increase the success of myoblast transplantation.