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Preconditioning of skeletal muscle against contraction-induced damage: the role of adaptations to oxidants in mice
Adaptations of skeletal muscle following exercise are accompanied by changes in gene expression, which can result in protection against subsequent potentially damaging exercise. One cellular signal activating these adaptations may be an increased production of reactive oxygen and nitrogen species (R...
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Published in: | The Journal of physiology 2004-11, Vol.561 (1), p.233-244 |
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Main Authors: | , , , , , , , |
Format: | Article |
Language: | English |
Subjects: | |
Citations: | Items that this one cites Items that cite this one |
Online Access: | Get full text |
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Summary: | Adaptations of skeletal muscle following exercise are accompanied by changes in gene expression, which can result in protection
against subsequent potentially damaging exercise. One cellular signal activating these adaptations may be an increased production
of reactive oxygen and nitrogen species (ROS). The aim of this study was to examine the effect of a short period of non-damaging
contractions on the subsequent susceptibility of muscle to contraction-induced damage and to examine the changes in gene expression
that occur following the initial contraction protocol. Comparisons with changes in gene expression in cultured myotubes following
treatment with a non-damaging concentration of hydrogen peroxide (H 2 O 2 ) were used to identify redox-sensitive genes whose expression may be modified by the increased ROS production during contractions.
Hindlimb muscles of mice were subjected to a preconditioning, non-damaging isometric contraction protocol in vivo . After 4 or 12 h, extensor digitorum longus (EDL) and soleus muscles were removed and subjected to a (normally) damaging
contraction protocol in vitro . Muscles were also analysed for changes in gene expression induced by the preconditioning protocol using cDNA expression
techniques. In a parallel study, C 2 C 12 myotubes were treated with a non-damaging concentration (100 μ m ) of H 2 O 2 and, at 4 and 12 h following treatment, myotubes were treated with a damaging concentration of H 2 O 2 (2 m m ). Myotubes were analysed for changes in gene expression at 4 h following treatment with 100 μ m H 2 O 2 alone. Data demonstrate that a prior period of non-damaging contractile activity resulted in significant protection of EDL
and soleus muscles against a normally damaging contraction protocol 4 h later. This protection was associated with significant
changes in gene expression. Prior treatment of myotubes with a non-damaging concentration of H 2 O 2 also resulted in significant protection against a damaging treatment, 4 and 12 h later. Comparison of changes in gene expression
in both studies identified haem oxygenase-1 as the sole gene showing increased expression during adaptation in both instances
suggesting that activation of this gene results from the increased ROS production during contractile activity and that it
may play a role in protection of muscle cells against subsequent exposure to damaging activity. |
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ISSN: | 0022-3751 1469-7793 |
DOI: | 10.1113/jphysiol.2004.069914 |