Figure 3.

Short-term exposure to TFN suppresses oxygen consumption and ROS production in PWR-1E and DU-145 cells. (A) The DU-145 and PWR-1E cells were treated with Me₂SO (control) or 50 µM TFN in fresh culture medium for 4 hours and examined for oxygen consumption as described in Figure 1C. *P < .05 compared with the DU-145 control; **P < .01 compared with the PWR-1E control. (B) PWR-1E and DU-145 cells cultured in six-well tissue culture plates were exposed to 50 µM TFN or to an equal volume of the vehicle Me₂SO (control) as described in panel (A). The medium was removed and replaced with Krebs-Ringer buffer containing 10 µg/ml 2′,7′-dichlorofluorescin diacetate. Fluorescence emission at 538 nm (representing DCF production) was measured immediately after mixing (time 0) and subsequently at 30-minute intervals during a 150-minute period. The spectrofluorimeter preformed 12 fluorescence measurements per well and provided the mean DCF fluorescence value.