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Updated: May 25, 2026

Measurement of Insulin- and Contraction-Stimulated Glucose Uptake in Isolated and Incubated Mature Skeletal Muscle from Mice
Published on: May 16, 2021
p38γ activity is required for maintenance of slow skeletal muscle size
William H Foster1, James G Tidball, Yibin Wang
1Molecular, Cellular, and Integrated Physiology Program, University of California at Los Angeles, Los Angeles, California, USA.
Introduction:
p38γ kinase is highly enriched in skeletal muscle and is implicated in myotube formation. However, the activation status of p38γ in muscle is unclear.
Methods:
p38γ activity in slow and fast adult mouse skeletal muscle tissue was examined, as was the impact of p38γ deficiency on muscle development and gene expression.
Results:
p38γ is preferentially activated in slow muscle, but it is inactive in fast muscle types. Furthermore, the loss of p38γ in mice led to decreased muscle mass associated with a smaller myofiber diameter in slow muscle, but there was no impact on fast muscle in either mass or myofiber diameter. Finally, p38γ-deficient muscle showed selective changes in genes related to muscle growth in slow muscle fibers.
Conclusion:
This study provides evidence that p38γ is selectively activated in slow skeletal muscle and is involved in the normal growth and development of a subset of skeletal muscle.
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