Figure 4.

Cyc induced apoptosis of granulosa cells in growing follicles and Mel prevented this apoptosis. (A) Three-week-old ICR mice were injected i.p. with Cyc 12 or 24 h after injection of PMSG, and apoptosis in ovarian tissues was detected by TUNEL kit at 8, 12, 24, and 36 h after Cyc injection. Regardless of whether Cyc was injected 12 or 24 h after PMSG injection, apoptotic peak of granulosa cells in ovary appeared 12 h after Cyc intervention, which was not related to the time of PMSG administration. Mice in control group were injected with Sal instead of Cyc, and the apoptotic peak of granulosa cells appeared 48 h (PMSG 12 h + Sal 36 h, or PMSG 24 h + Sal 24 h) after injection of PMSG. DNase I treatment was used for positive control of TUNEL assay. There were four three-week-old female mice in each group; Bar = 200 μm. (B) TUNEL fluorescence intensity in ovaries of 3-week-old ICR mice 8, 12, 24 and 36 hours after Cyc injection. The mice received Cyc chemotherapy 12 hours after injection of PMSG. (C) TUNEL fluorescence intensity in ovaries of 3-week-old ICR mice 8, 12 and 24 hours after Cyc injection. The mice received Cyc chemotherapy 24 hours after injection of PMSG. (D) Mel prevented apoptosis of granulosa cells 12 h after Cyc chemotherapy. There were four three-week-old female mice in each group; Bar = 200 μm. (E) TUNEL fluorescence intensity in ovaries of 3-week-old ICR mice in Sal, Cyc, Mel and Mel+Cyc groups 12 hours after Cyc injection.