Ovarian histology of mice at the end of the 21 day-treatment. (A1,A2) Ovarian sections from mice that received plain water (negative control), showing primary, secondary, and tertiary follicles as well as a corpus luteum (A1). These features are typical of normally cycling mice. (B1,B2) Sections from mice subjected to 21-day treatment with DCIns 250, showing primary, secondary, tertiary and cystic follicles devoid of oocytes. These features resemble typical signs of PCOS. (C1,C2) Sections from mice subjected to 21-day treatment with letrozole (positive controls), showing paucity of follicles and a large cyst, typically modeling human PCOS. (D1,D2) Sections from mice subjected to 21-day treatment with DCIns 500, showing secondary and tertiary follicles as well as follicles with signs of hyperproliferation and extension of the stromal compartment. (E1,E2) Sections from mice subjected to 21-day treatment with DCIns 1000, showing paucity of secondary and tertiary follicles as well as large follicles with signs of hyperproliferation and extension of the stromal compartment. Hematoxylin-eosin. Scale bars, 100 μm.