Figure 3.

DPI and NAC inhibit GnRH-induced MAPK1/3 and JNK activation. Serum-starved LβT2 cells were preincubated with the NOX-specific inhibitor apocynin at 500 μM, the general NOX/DUOX inhibitor DPI at 5 μM, or the nonspecific ROS scavenger NAC at 10 mM for 30 minutes. Cells were then treated with 10 nM GnRH for 5 minutes (MAPK1/3) and 30 minutes (JNK). Both phosphophorylated (p) MAPK1/3 and phosphophorylated JNK were measured by Western blotting and quantitative chemiluminescence. A and B, top, Representative Western blot images using an antibody to phosphorylated MAPK1/3 or JNK and then stripped and reblotted with an antibody to total MAPK1/3 or total JNK. Reported values are determined by the combined ratio of phosphorylated MAPK1/3 to total MAPK1/3. Data show mean values ± SEM normalized to the vehicle control from 4 independent determinations. Letters represent significant differences (P < .05) by ANOVA followed by the Tukey multiple comparison test. Groups with different letters are significantly different from each other. M, Protein size marker.