Fig. 4. Effects of endosulfan on the AhR upstream signaling pathway. (A) Effects of endosulfan on CaMK protein activation in Hepa-1c1c7 cells. Cells were treated with endosulfan (Endo) for 5min. Phosphorylated CaMKIa at threonine 177 (P-CaMKIα) was then analyzed by Western blotting, and β-actin expression was measured as a loading control. (B-C) Effects of endosulfan on PKC phosphorylation in Hepa-1c1c7 cells. Cells were treated with endosulfan for 10 min (B). Cells were pretreated with W7 and subsequently treated with endosulfan for 10 min (C). P-PKC was then analyzed by Western blotting, and β-actin expression was measured as a loading control. (D) Cells were pretreated with W7 or Gö 6983 (Gö) and treated with endosulfan for 24 h. CYP1A1 protein levels were then analyzed by Western blotting, and β-actin expression was measured as a loading control. Each blot in this figure is representative of three independent experiments with similar results.