To observe dystrophin formation and histological improvement in dystrophic muscle of mdx mouse after normal myoblast injection.

Cultured myoblasts from genetically normal rats were injected into the right quadriceps femoris of a 6-week-old mdx mouse (n=9). dPBS was injected into the left quadriceps femoris as a control. One, 2, and 3 months after injection, The control and experimental group were compared histologically and by dystrophin immunostaining.

When compared with controls 3 months postoperatively, quadriceps femoris in the experimental group exhibited greater cross-sectional area and total fiber number, and the experimental animals contained more normal-appearing and less abnormalappearing fibers than the control group. Most of the fibers in the experimental group showed positive results in dystrophin immunostaining, whereas immunostaining of mdx muscle fibers in the control group was completely negative.

This study shows that normal myoblast injection improved the muscle architecture histologically and produced dystrophin protein in dystrophic muscle.