Relationships between percentages of round cells and proliferation rates, pyknotic rates or steroidogenesis of GC cultured on substrata containing different ratios of LN and RGD peptides. GC were cultured for 144 h as described in legend of Figure 5. (a): proliferation rates of GC from small follicles at 48 h of culture. (b): pyknotic rates of GC from small (solid circles) and large (empty circles) follicles at 48 h of culture. (c): steroid secretion by GC from large follicles between 96 h and 144 h; solid triangles: estradiol secretion, expressed in pg/50 × 103 cells/48 h, solid squares: progesterone secretion, expressed in ng/50 × 103 cells/48 h. Each data point is the mean of 7 independent experiments.