Contractile function and low-intensity exercise effects of old dystrophic (mdx) mice.
A Hayes, DA Williams
American Journal of Physiology | Published : 1998
Old mdx mice display a severe myopathy almost identical to Duchenne's muscular dystrophy. This study examined the contractile properties of old mdx muscles and investigated any effects of low-intensity exercise. Isometric contractile properties of the extensor digitorum longus (EDL) and soleus muscles were tested in adult (8-10 mo) and old (24 mo, split into sedentary and exercised groups) mdx mice. The EDL and soleus from old mdx mice exhibited decreased absolute twitch and tetanic forces, and the soleus exhibited a > 50% decrease in relative forces (13.4 +/- 0.4 vs. 6.0 +/- 0.9 N/cm2) compared with adult mice. Old mdx muscles also showed longer contraction times and a higher percentage of ..View full abstract