Figure 5. Effect of inhibitors on NOX4 activity.

T-REx™ NOX4 cells were induced with 1 μg/ml tet for 24 h before measurements. DPI (a), apocynin (b), gliotoxin (c) or thioridazine (d) were added at different concentrations, and NOX4 activity was measured by Amplex Red fluorescence. Fluorescence values from 50000 cells were recorded after 20 min and normalized to those obtained from NOX4-induced cells without inhibitor. A four-parameter Hill sigmoid curve was used for the determination of IC₅₀ values. Results are means±S.E.M. (n=3).