Ovaries and follicles immunostained for AMH in DHEA-treated and control rats. (A ~ F) Light micrographs of hematoxylin/eosin-stained whole rat ovary sections: vehicle (control) administration for 7 days (A), 15 days (B) or 30 days (C); DHEA administration for 7 days (D), 15 days (E) or 30 days (F). At 7 days, the ovaries of both groups (A, D) contain numerous follicles and were similar in configuration. The day-15 DHEA ovary has more small follicles than control ovaries (B, E) and exhibits a polycystic-like morphology. Day-30 control ovaries have fewer follicles than any of the other groups (C). Day 0-30 DHEA ovaries have more cystic follicles than ovaries of the day-30 control and day-15 DHEA groups (C, E, F). These micrographs are at different magnifications. (G ~ L) AMH immunostaining in ovaries from DHEA-treated and control rats: (G) Strong diffuse expression of AMH (+) in primordial follicles; (H) Mild sparse expression (±) in primordial follicles; (I) No expression (−) in primordial follicles; (J) Strong expression in primary the follicles; (K) Moderate expression in the late preantral follicles; (L) Strong expression in early antral follicles.