RADIATION INHIBITION OF MDX MOUSE MUSCLE REGENERATION - DOSE AND AGE FACTORS

A single hind limb was irradiated with 12, 18, 24, or 30 Gy in mdx and C57 mice aged 12, 21, or 42 days to determine regeneration inhibition dose-response curves in different aged dystrophic mice and to charact erize radiation side-effects in normal mice. The anterior tibial muscl e mass (8 weeks postirradiation) and percent central nucleated (i.e., regenerated) muscle fibers were measures of regeneration inhibition. T wenty-one-day-old mdx mice irradiated with 18 Gy had complete inhibiti on of muscle regeneration, but 30 Gy only partially blocked regenerati on in mdx mice irradiated at 12 and 42 days in age. In working to prod uce a clinically relevant model for Duchenne dystrophy, it is crucial to regard mouse age as a major factor in determining radiation effects on mdx muscle regeneration. (C) 1995 John Wiley and Sons, Inc.