DHT-treated rats show higher body weight gain, disrupted estrous cycles, insulin resistance, responsiveness to gonadotropin and ovarian features. (A) Weight gain of DHT-treated rats are significantly higher than CTL animals after 5 weeks DHT implant (***, P < 0.001). (B) Estrous cycle was evaluated by microscopic analysis of the predominant cell type in vaginal smears obtained daily from 10–11 weeks post-implantation. Estrous cycle patterns were shown in two representative rats from each group. P: proestrous; E: estrous; M: metestrous; D: diestrous. 94% of DHT-treated rats show irregular estrous cycle versus 22% in CTL rats. (C) Insulin Sensitivity Test (IST): Animals were injected with insulin (0.2U/100g Body weight) through tail vein and plasma glucose levels were measured by glucose meter at the time indicated. Data was transformed by Log K
ITT for analysis. K
ITT=0.693/t1/2x100, t1/2 represents the half-life of glucose decay after insulin injection (†P < 0.05). (D) 20 IU eCG was injected to DHT-treated rats for designated time (0–30 h) and ovarian weight was assessed. Reduced ovarian weight in DHT-treated rats was reversed by eCG treatment in vivo (*, P <0.05; ** P < 0.01). (E) Corpus luteum and cystic follicle numbers were counted in the maximal longitudinal ovarian sections and percentage of FC or CL over the total follicle structure per section were presented. Data showed that PCOS rats was bearing large number of cystic follicles accompanying with anovulation (CL percentage in control vs DHT was 35%, 4%, *P < 0.05; cystic follicles (FC) was 7% vs 43%, respectively, # P < 0.05).