Figure 10.

RA + TPA stimulation of VEGF requires production of ROS. HESC were treated overnight with the compounds as indicated in the absence or presence of the antioxidant NAC. Concentrations of RA and TPA were as shown in the legend to Fig. 1. Results show that NAC blocked secretion of VEGF by more than 80%. An increase of ROS by H₂O₂ (200 μm) in combination with TPA was seen to mimic the effect of RA + TPA on VEGF secretion. NAC similarly inhibited the VEGF-stimulating effects of H₂O₂ + TPA. *, Significant decrease from similarly treated cultures without NAC. Con, Control.