Figure 4
Effect of cytochalasin D on steroidogenesis of GC from large follicles cultured on LN substratum. GC from large follicles were cultured for 144 h on LN as described in legend of Figure 2. (a) and (b): estradiol (E2) and progesterone (P4) secretions between 96 h and 144 h of culture; data are expressed as percentages of control (100%, empty bars, corresponding to 0.40 ± 0.17 ng/50 × 105 cells/48 h for E2 and 700 ± 176 ng/50 × 105 cells/48 h for P4) and represent mean ± SEM of 5 independent experiments; solid bars: with anti-α6 IgG (0.5 μg/ml) in culture medium; in each graph, different letters indicate significant differences (p < 0.05); *** : p < 0.001, compared to control. (c) and (d): expression of P450scc and 3βHSD enzymes in GC at 144 h of culture, in control or in the presence of anti-α6 IgG or cytochalasin D (0.5 μg/ml) in culture medium; results show representative western immunoblotting experiments performed on 5 μg of GC extracts; data correspond to quantification of autoradiograms in arbitrary units (control mean = 100) and represent mean ± SEM of 5 independent experiments; * : p < 0.05, ** : p < 0.01, treated vs. control.