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Reactive oxygen species (ROS) stimulate AMPK activity in skeletal muscle.
Author(s) -
Smith Melissa A,
Arbogast Sandrine,
Smith Jeffrey,
Moylan Jennifer,
Reid Michael B
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.4.a802
Subject(s) - ampk , skeletal muscle , chemistry , protein kinase a , catalase , reactive oxygen species , phosphorylation , amp activated protein kinase , nadph oxidase , medicine , superoxide dismutase , endocrinology , glucose uptake , biochemistry , microbiology and biotechnology , oxidative stress , insulin , biology
Exogenous ROS stimulate insulin‐independent glucose uptake by skeletal muscle. AMP‐activated protein kinase (AMPK) is a mediator of insulin‐independent glucose transport. This study tested the hypothesis that endogenous ROS modulate AMPK in skeletal muscle. Oxidant activity was measured by use of 2′,7′ dichlorofluorescein. AMPK activity was measured by immunoblotting with a phosphospecfic antibody and by immunoprecipitation followed by a kinase reaction with SAMS peptide substrate. We demonstrate that stretching murine extensor digitorum longus (EDL) 90 to 110% optimal length increases oxidant activity (+171%, p<0.01). We show that 10 min cyclic stretch increases oxidant activity (+164%, p<0.01) and induces phosphorylation of AMPK in C2C12 myotubes (+98% control; p <0.01); 30 min stretch does not (p<0.05). Pretreatment with 1000 U/mL catalase suppresses AMPK phosphorylation (−385% control; p<0.01); 1000 U/mL superoxide dismutase (SOD) does not (p<0.01). These data indicate exposure to H 2 O 2 and stretch stimulates AMPK activity. This suggests that muscle‐derived ROS may function as second messengers to mediate stretch induced AMPK effects. Supported by DK 066232.