Pituitary cells in culture were incubated with vehicle (control) or 1 nM E2 for 6 h with or without 2 µM actinomycin D (Act D), a transcription inhibitor, 30 min before treatment. (A), mRNA expression was evaluated by PCR. Top, a representative PCR. Bottom, Average densitometric values. Bars represent mean ± SE of relative units corresponding to α1 (open bars) and β1 (black bars) mRNA densitometric values normalized to β-actin, as percent of control (n = 3). (B), protein expression was evalulated by western blot. Top, a representative western blot. Bottom, Average densitometric values. Bars represent mean ± SE of relative units corresponding to α1 (open bars) and β1 (black bars) protein densitometric values normalized to β-actin, as percent of control (n = 3). ANOVA followed by Tukey's test, *P<0.05, **P<0.01 vs. respective controls; ΔP<0.05 vs. E2.