Effects of TGF-β1 and estrogen on urethral elastin mRNA expression. Urethral cells were isolated from female rats, treated with TGF-β1 and/or estrogen, and analyzed by real-time PCR. A. Dosage response of elastin mRNA expression to TGF-β1. “Relative expression” is the ratio of elastin versus GAPDH expression. B. Elastin mRNA expression in urethral cells treated with 1 ng/ml TGF-β1 (TGF), 10 nM estrogen (E2), 10 nM estrogen for 1 h and then 1 ng/ml TGF-β1 for 16 h (E2/TGF), or 1 ng/ ml TGF-β1 for 1 h and then 10 nM estrogen for 16 h (TGF/E2). “Relative expression” is the ratio of elastin versus GAPDH expression. * indicates significant difference (p<0.05) compared to TGF-β1 alone. The data are the average of 3 independent experiments.