Effects of chronic ethanol and NAC treatment on upstream mediators of insulin/IGF signaling. Liver protein homogenates were used to measure immunoreactivity corresponding to (A) insulin receptor (R), (B) IGF-1R, (C) IRS-1, (D) pYpY1162/1163-IR, (E) pYpY1135/1136-IGF-1R, (F) pS312-IRS-1 with a bead-based Multiplex ELISA platform (see Methods and Methods). (G–I) In addition, the phosphorylated/total protein ratios for were calculated to assess relative levels of phosphorylation of each protein. Data were analyzed statistically using one-way ANOVA with the Tukey multiple comparison tests. Significant P-values are indicated within the panels.