Figure 1

Confirmation of AhR activation by components of Aroclor 1254 by CYP1A1 western blotting experiments and by determining EROD enzyme activity. A: Western blot using an antibody against CYP1A1. Protein expression of CYP1A1 in cultures of human hepatocytes treated with three different concentrations of Aroclor 1254 (10 μM, 20 μM, and 50 μM) for 72 h, respectively. Lane 1: control, untreated; lane 2: 10 μM Aroclor 1254; lane 3: 20 μM Aroclor 1254; lane 4: 50 μM Aroclor 1254. B: EROD-enzyme activity. Enzyme activity of CYP1A1 in cultures of human hepatocytes treated with 20 μM Aroclor 1254 for 24 h, 48 h and 72 h, respectively. The de-ethylation product resorufin was determined fluorometrically. Results are mean and SD of three dishes.