Effect of Testosterone on Insulin Stimulated IRS1 Ser Phosphorylation in Primary Rat Myotubes—A Potential Model for PCOS-Related Insulin Resistance
2009

Testosterone's Effect on Insulin Action in Rat Muscle Cells

publication Evidence: moderate

Author Information

Author(s): Michael C. Allemand, Brian A. Irving, Yan W. Asmann, Katherine A. Klaus, Laura Tatpati, Charles C. Coddington, K. Sreekumaran Nair

Primary Institution: Mayo Clinic Graduate School of Medicine

Hypothesis

Does testosterone increase serine phosphorylation of IRS-1 in skeletal muscle, contributing to insulin resistance?

Conclusion

Testosterone exposure increases serine phosphorylation of IRS-1, suggesting a link to insulin resistance in a hyperandrogenic environment.

Supporting Evidence

  • Testosterone exposure increased IRS-1 Ser636/639 phosphorylation in muscle cells.
  • Low-dose testosterone significantly enhanced insulin-induced phosphorylation of mTOR and S6K.
  • High-dose testosterone reduced insulin-induced phosphorylation of mTOR and S6K.

Takeaway

This study found that testosterone can make it harder for cells to respond to insulin, which is important for understanding conditions like PCOS.

Methodology

Rat skeletal muscle myotubes were treated with insulin after pre-exposure to testosterone, and protein phosphorylation was measured using Western blot.

Limitations

The in vitro model may not fully represent in vivo biology.

Statistical Information

P-Value

p=0.042

Statistical Significance

p<0.05

Digital Object Identifier (DOI)

10.1371/journal.pone.0004274

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