Effect of noise exposure on insulin signaling in the gastrocnemius muscle and liver.

<p>(A) Representative images of gastrocnemius sections stained for GLUT4 (green) and DAPI (blue). The insets show higher magnifications of GLUT4-enriched cells signified by arrowheads. All images were collected with a 20× objective. (B-C) The relative GLUT4 fluorescence intensity in gastrocnemius muscle cells 20 min after exogenous insulin injection after 2 weeks of treatment (B) and 8 weeks of treatment (C) normalized to background and compared across groups. (D) The levels of Ser³⁰⁷ phosphorylated IRS-1 (p^S307-IRS1), total IRS1, Ser⁴⁷³ phosphorylated AKT (p^S473-AKT) and total AKT detected by immunoblotting. (E-L) Phosphorylation levels of IRS1and AKT quantified and normalized to corresponding CD-C group. The average of each CD-C group was set to 1. The values are presented as the means ± SEM of 8 mice per group. *<i>p</i> < 0.05, **<i>p</i> < 0.01 and ***<i>p</i> < 0.001 indicate significance in the Tukey’s <i>post hoc</i> comparisons between each group and the CD-C after one-way ANOVA.