Figure 1. H₂O₂ treatment induces D-cyclins down-modulation. A) HUVEC were treated with 400 µmol/l H₂O₂ for the indicated time, followed by Western blotting. Graph shows cyclin D1 protein expression normalized for -tubulin levels and expressed as % of untreated cells (*P<0.001 vs. control; n=6–16). B) Dose-dependent down-modulation of D-cyclins. HUVEC were incubated for 2 h with H₂O₂, followed by immunoblots. Graph shows cyclin D1 protein expression levels (*P<0.001 vs. control; n=3–7).