Metformin modulates IRS-1 levels and Akt phosphorylation. (A-C) BxPC-3 and (D-F) MIAPaCa-2 cells were treated in 1% FBS SFM with either normal (5 mM) or high (25 mM) glucose, with or without metformin for 24 h and processed for immunoblot analysis using antibodies against IRS-1, pAkt and Akt. GAPDH is shown as a loading control. One representative blot is shown. Graphs display densitometry measurements of relative levels of IRS-1 and pAkt at 5 mM (black bars) or 25 mM (striped bars) glucose conditions and represent means ± SE of three independent experiments. P-values are based on two-way ANOVA with Bonferroni post hoc test. N.S. not significant.