↵3-a Antagonism of TCDD-induced luciferase was determined at 150 pM TCDD plus 1 nM – 1 μM of each compound. Cells were harvested after 4 h of exposure (see Materials and Methods). Values shown are mean ± standard error from nonlinear fit to data from triplicate measurements.

↵3-b Luciferase induction by each compound alone at 1 μM as a percent of induction by 1 nM TCDD (tested concurrently for each experiment).

↵3-c Cells were exposed to 1 μM of each compound for 4 h, trypsinized, and aliquots of cells transferred to fresh plates; after 7 days, cells were fixed to the plates (methanol), stained with crystal violet, and colonies counted. Expressed as percent of solvent control plates, average of 3 plates.