PND4 rat ovaries were cultured for 4 d in control media and thereafter exposed to a single 1% DMSO (vehicle control) or DMBA (12.5 nM or 75 nM). Following 1, 2 or 4 additional days of culture, mRNA was isolated and (A) Cyp2e1, (B) Gstp, (C) Gstm, and (D) Ephx1 levels evaluated by quantitative RT-PCR. Values represent fold-change ± SEM relative to a control value of 1, normalized to Gapdh. * = different from control, P < 0.05; # = P < 0.1.