Figure 3. Time course of the inhibitory effects of 17β-estradiol and progesterone on IL-1β–induced collagen degradation by corneal fibroblasts. Cells were cultured for the indicated times in collagen gels in the absence or presence of IL-1β (0.1 ng/ml) and either 17β-estradiol (10 μM) or progesterone (10 μM) as indicated. The amount of degraded collagen was then determined. Data are means±SEM of quadruplicates from an experiment that was repeated three times with similar results. *p<0.05 (Student’s t test) for cells incubated with IL-1β plus 17β-estradiol or progesterone versus the corresponding value for those incubated with IL-1β alone.