Figure 7. Effects of repeated superovulation on oxidative damage and antioxidant enzymes in both groups. Oxidative stress related oxidative damage in interstitial cells was scored using immunostaining for oxidative damage markers, as described in the Methods section. (A) Representative images of immunostaining (dark brown) for each oxidative damage marker in interstitial cells: Oxidative DNA damage (8-OHdG), lipid peroxidation (4-HNE) and protein oxidation (NTY) in the ovaries of the NC group, RS group and negative control and positive control groups. All original magnifications are x200. (B-C) The percentages of positive stained granulosa cells in healthy or atretic follicles. (D-E) The percentages of positive theca cells in the healthy or atretic follicles. (F) The percentages of positive interstitial cells in the ovaries. (G) The protein expression of the antioxidant gene SOD2 was significantly increased in the RS group. Values are expressed as the mean ± SEM. *P<0.05 compared to the NC group.