Media estradiol (E2) concentrations (pg/ml) in fast-grow and slow-grow follicles in progestin (P, A) and E2 (B) replacement experiments at Week 5 of culture. CONT, control, TRL, trilostane, LP, low-dose P, HP, high-dose P, LE, low-dose E2 and HE, high-dose E2. Data are presented as mean ± SEM. Different capital and lower case letters represent differences in fast-grow and slow-grow follicle populations, respectively, between treatment groups in each experiment. Asterisk represents differences between fast-grow and slow-grow follicles within the same treatment group.