Figure 7.

The IRS-1/Akt signaling pathway is down-regulated in cardiac muscle of STZ-treated diabetic mice. The components of the IRS-1/Akt signaling pathway were measured in cardiac muscle extracts in control (Ctrl), diabetic (STZ), or insulin-treated diabetic (STZ+Ins) mice. IRS-1, Akt, and p-Akt Ser473 were measured by Western analyses. IRS-1 phosphorylation was measured by immunoprecipitating with an antiphosphotyrosine antibody, followed by Western analysis for IRS-1. The bar graphs show the ratio of phosphorylated to total IRS-1 (left) or Akt (right) presented as a percent of control values. Data are reported as the means ± se (n = 6 per group). *, P < 0.05 or **, P < 0.01 vs. control.