Figure 2

Alteration of insulin signaling cascades in liver tissue of rats after MI. (A) Tyrosine phosphorylation of IR β-subunit. Liver tissue lysates were separated by SDS-PAGE, and Western blot was performed using specific anti-tyrosine-phospho-IR β-subunit and anti-IR β-subunit. (B) Tyrosine phosphorylation of IRS1 and attachment of PI3K p85 subunit with IRS1. Liver tissue lysates were immunoprecipitated with specific anti-IRS1 and then subjected to Western blot using specific anti-IRS1, anti-phospho-tyrosine (P-Tyr-100) and anti-PI3K p85 subunit. (C) Serine phosphorylation of Akt (ser 473). Liver tissue lysates were separated by SDS-PAGE and Western blot was performed using specific anti-phospho-Akt (ser 473) and anti-Akt. Left panel, representative immunoblots are shown. Right panel, quantification of phosphorylation blots relative to their corresponding loading. (A) Tyrosine phosphorylation of IR β-subunit relative to IR β-subunit, (B) Tyrosine phosphorylation of IRS1 relative to IRS1 and IRS1-p85 subunit relative to IRS1, (C) Serine phosphorylation of Akt (ser 473) relative to Akt. IP immunoprecipitation; IB, immunoblotting; I, insulin (with insulin stimulation); B, basal (without insulin stimulation). Values presented are means ± SEM of 4 to 5 samples in each group. *P < 0.05 versus control group with insulin stimulation. ^#P < 0.05 versus control group without insulin stimulation.