TY - JOUR
T1 - Voluntary exercise decreases progression of muscular dystrophy in diaphragm of mdx mice
AU - Dupont-Versteegden, E. E.
AU - McCarter, R. J.
AU - Katz, M. S.
PY - 1994
Y1 - 1994
N2 - Effects of voluntary wheel running on contractile properties of diaphragm (DIA) and soleus (SOL) of dystrophic (mdx) and control (C57BL/10SNJ) mice were evaluated. In particular, we tested the hypothesis that daily voluntary running is not deleterious to muscle function in mdx mice. Both groups of mice ran extensively (control mice ~7 km/day, mdx mice ~5 km/day). Exercise increased maximal specific tetanus tension of mdx DIA from 1.02 ± 0.04 to 1.33 ± 0.06 kg/cm2 but did not restore it to the control level (2.55 ± 0.17 kg/cm2). Maximal tetanus tension of sedentary mdx SOL (2.41 ± 0.17 kg/cm2) was reduced compared with control (3.10 ± 0.15 kg/cm2) and was not altered by running activity. Optimal length was significantly lower in DIA of mdx mice, and exercise did not change this. Fatigability and contractile properties of muscles measured in vitro were not altered by running activity with the exception of increased contraction time in mdx DIA. In conclusion, extensive wheel running is not deleterious to muscle function in mdx mice contrary to predictions of the 'work overload' theory of muscular dystrophy. Rather, this exercise is beneficial for active tension generation of mdx DIA, the muscle most closely resembling muscles of patients with Duchenne muscular dystrophy.
AB - Effects of voluntary wheel running on contractile properties of diaphragm (DIA) and soleus (SOL) of dystrophic (mdx) and control (C57BL/10SNJ) mice were evaluated. In particular, we tested the hypothesis that daily voluntary running is not deleterious to muscle function in mdx mice. Both groups of mice ran extensively (control mice ~7 km/day, mdx mice ~5 km/day). Exercise increased maximal specific tetanus tension of mdx DIA from 1.02 ± 0.04 to 1.33 ± 0.06 kg/cm2 but did not restore it to the control level (2.55 ± 0.17 kg/cm2). Maximal tetanus tension of sedentary mdx SOL (2.41 ± 0.17 kg/cm2) was reduced compared with control (3.10 ± 0.15 kg/cm2) and was not altered by running activity. Optimal length was significantly lower in DIA of mdx mice, and exercise did not change this. Fatigability and contractile properties of muscles measured in vitro were not altered by running activity with the exception of increased contraction time in mdx DIA. In conclusion, extensive wheel running is not deleterious to muscle function in mdx mice contrary to predictions of the 'work overload' theory of muscular dystrophy. Rather, this exercise is beneficial for active tension generation of mdx DIA, the muscle most closely resembling muscles of patients with Duchenne muscular dystrophy.
KW - Duchenne muscular dystrophy
KW - contractile properties
KW - endurance training
KW - muscles
KW - respiratory muscle
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U2 - 10.1152/jappl.1994.77.4.1736
DO - 10.1152/jappl.1994.77.4.1736
M3 - Article
C2 - 7836193
AN - SCOPUS:0027984229
SN - 8750-7587
VL - 77
SP - 1736
EP - 1741
JO - Journal of Applied Physiology
JF - Journal of Applied Physiology
IS - 4
ER -