Fig. 3.

H₂O₂ (0.03–0.3 mM) activates mTOR but concentrations > 1 mM are required for activation of PKB/Akt. Cardiomyocytes were exposed to the concentrations of H₂O₂ indicated for 15 min (A) and (C), or to 0.2 mM H₂O₂ for the times shown (B). Samples were immunoblotted with antibodies to phosphorylated (P)-mTOR(Ser²⁴⁴⁸), P-mTOR(Ser²⁴⁸¹), total mTOR, P-PKB/Akt(Ser⁴⁷³), P-PKB/Akt(Thr³⁰⁸) or total PKB/Akt as indicated. Representative blots are shown in the panels on the left, with densitometric analysis and the ratio of Phospho−/Total proteins in the graphs on the right. Results are means ± SEM [n = 4 (A) and (B) or n = 3 (C) independent myocyte preparations]. *p < .05, **p < .01 and ***p < .001 relative to unstimulated cells (one-way ANOVA with Dunnett's post-test).