Successful treatment of murine muscular dystrophy with the protease inhibitor bestatin.

Continued administration of the dipeptide protease inhibitor Bestatin to 34 mice with genetic muscular dystrophy from the onset of clinical deficit, cured about half of the animals within 3 months. Cessation of treatment in the recovered mice at age 4 months was not followed by relapse. Examinations of these mice revealed recovery of (1) weight gain and life span, (2) muscle strength, and (3) marker enzyme activities in skeletal muscle and serum, as well as (4) disappearance of myopathological features characteristic of the disease such as necrosis of muscle fibers, centralization or a chain like arrangement of nuclei, or a marked infiltration of collagenous fibers. Finally, (5) the genetic confirmation of the animals which attained remission was confirmed to be dy/dy.