Effect of β-estradiol on type I/III collagen ratio. Type I/III collagen mRNA (ng/μg total RNA) was quantified by RT-PCR analysis after 24 hours of β-estradiol stimulation. White bars: no estrogen, grey bars: 0.025 ng/ml β-estradiol, black bars: 0.25 ng/ml β-estradiol. A: fibroblasts derived from female patients; B: fibroblasts derived from male patients; Data are presented as means +/- standard deviation; *p < 0.05 vers. CFs.