FORCE AND STIFFNESS OF OLD DYSTROPHIC (MDX) MOUSE SKELETAL-MUSCLES

It has recently been suggested, based on studies of tissue pathology, that the limb muscles of old mdx mice may be a good model for the musc ular changes seen in human Duchenne muscular dystrophy. To test this h ypothesis, we measured force and stiffness of soleus and extensor digi torum longus (EDL) muscles of old (20-21 months) mdx mice and age-matc hed controls. The mdx and control muscles generated similar twitch, te tanic, and eccentric forces. They were also equally stiff. The results show that the mechanics of aged mdx limb muscles differ greatly from Duchenne muscular dystrophy in humans, and disagree with the hypothesi s. (C) 1998 John Wiley & Sons, Inc.