Figure 3
Progesterone disrupted the LH surge in PMSG-primed female rats. Representative examples illustrating levels of LH in oil vehicle (Veh, A) or progesterone (Prog, B) treated animals at the expected time of the PMSG-induced LH surge on the afternoon of day 2. (C) Mean serum progesterone measured at 18:00 h on day 0 (day 0, PMSG treatment) after injection with vehicle or progesterone in PMSG-primed female rats. (D) Mean serum oestradiol level measured at 18:00 h on day 1 (day 0, PMSG treatment) after injection with vehicle or progesterone in PMSG-primed female rats. (E) Significant difference in peak LH levels at the time of the expected LH surge between oil controls and progesterone treated PMSG-primed animals. Baseline LH level at noon (12AM) on day 2 showed no difference. (F) Area under curve (AUC) analysis of LH levels at the time of the expected LH surge (12:00–20:00 h, day 2) in PMSG-primed female rats treated with oil vehicle or progesterone revealed a significant deference; n = 6 rats/group. Values were analysed by two-way ANOVA with group (Veh vs Prog). Results are presented as means ± SEM. *P < 0.05, Veh vs Prog; n = 5–7 per group.
