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Administration of insulin‐like growth factor‐I improves fatigue resistance of skeletal muscles from dystrophic mdx mice
Author(s) -
Gregorevic Paul,
Plant David R.,
Lynch Gordon S.
Publication year - 2004
Publication title -
muscle and nerve
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.025
H-Index - 145
eISSN - 1097-4598
pISSN - 0148-639X
DOI - 10.1002/mus.20082
Subject(s) - medicine , endocrinology , mdx mouse , skeletal muscle , muscle fatigue , duchenne muscular dystrophy , insulin like growth factor , diaphragm (acoustics) , muscular dystrophy , growth factor , dystrophin , electromyography , physical medicine and rehabilitation , receptor , physics , loudspeaker , acoustics
Muscle fatigue occurs in many neuromuscular diseases, including the muscular dystrophies, and it contributes to a loss of functional capacity and reduced quality of life for affected patients. An improvement in fatigue resistance has been observed in diaphragm muscles of mdx mice following insulin‐like growth factor‐I (IGF‐I) administration. Whether similar treatment can improve locomotor muscle function in mdx mice is not known. We examined the efficacy of IGF‐I administration (1 mg/kg daily s.c. for 8 weeks) on structural, metabolic, and functional properties of extensor digitorum longus (EDL) and soleus muscles of mdx mice, and tested the hypothesis that IGF‐I treatment would improve function in these muscles. After treatment, muscles were more resistant to fatigue during repeated maximal contractions than muscles from untreated mice, an improvement associated with increased muscle fiber succinate dehydrogenase activity in the absence of changes in cellular (single‐fiber) contractile activation characteristics. The findings have important clinical implications, not just for the dystrophinopathies, but for all neuromuscular pathologies where fatigue of locomotor muscles limits functional capacity and decreases quality of life. Muscle Nerve 30: 295–304, 2004