The expression of alpha-dystrobrevin and dystrophin during skeletal muscle regeneration.

The expression of alpha-dystrobrevin and dystrophin in rat tibialis anterior muscles was chronologically evaluated during a cycle of regeneration after myonecrosis induced by the injection of cardiotoxin. In immunohistochemical studies, alpha-dystrobrevin and dystrophin were first stained weakly at the sarcolemma of some regenerating muscle fibers on day 5. On day 7, alpha-dystrobrevin was still stained weakly, whereas dystrophin was stained conspicuously. After day 10, alpha-dystrobrevin and dystrophin were both stained conspicuously on almost all regenerating muscle fibers. In the Western blot analysis, alpha-dystrobrevin and dystrophin were first detected as visible bands on days 5 and 7, respectively. The bands of alpha-dystrobrevin and dystrophin both darkened sequentially up to day 10. The protein levels based on the densitometrical analysis of the bands on each day were converted to the percentage of the protein level on day 28, which was taken as 100%. The sequential line based on these data showed that alpha-dystrobrevin and dystrophin reached 50% of the protein level on day 28 by 6.6 and 5.3 days, respectively. These data provide evidence that alpha-dystrobrevin regenerates more slowly than dystrophin in skeletal muscle.