Myosins in murine muscular dystrophy.

Electrophoresis of intact myosin ATPases extracted from fast-twitch and slow-twitch muscles of dystrophic mice, and from control mice, was performed. The proportions of the lower ATPase myosin were increased in the dystrophic muscles. These results correlated with the abnormalities in the isometric myogram and the force/velocity relationships which have been described.