Figure 3.

TxA₂-induced AMPK activation is mediated by ROS production. TPr stimulation increases ROS production in VSMCs (a). ROS were determined by measuring DCF after incubation with either IBOP (1 µmol/L) or U46619 (1 µmol/L) for 10 minutes. Data are means±SEM (a, n=4 [♣P<0.05]; b, n=3 [♣P<0.05]). Infection of VSMCs with adenoviruses encoding catalase or SOD1 increased the expression of both catalase and SOD1 in VSMCs, respectively (b). The blot is representative of at least 3 blots of 3 independent experiments. Adenoviral overexpression of catalase increased catalase activity in VSMCs (b). Catalase activity was examined after 48 hours of infection with adenoviral GFP or catalase. Catalase activity is shown in nanomoles per minute per milliliter (means±SEM, n=3). ‡P<0.01 catalase vs GFP controls. Adenoviral overexpression of catalase suppresses IBOP-induced (1 µmol/L, 10 minutes) AMPK activation, whereas overexpression of SOD1 (Cu/Zn SOD) increases AMPK activation (c). The blot is representative of 3 blots from 3 individual experiments. Exogenous H₂O₂ at concentrations indicated for 10 minutes increases AMPK activation in VSMCs (d). Data are means±SEM (n=3). ♣P<0.05; ‡P<0.01, treated vs control cells.