A, mRNA levels of MAP3K8 and (B) P4 level in the culture medium at vehicle, 3 hours, 6 hours, and 12 hours after incubating the cells with 100 ng/mL LH. P4 level in the culture medium (C) and mRNA levels of MAP3K8 (D) at vehicle (0), 3 hours, 6 hours, and 12 hours after incubating the cells with 1 μg/mL PRL are shown. mRNA levels of MAP3K8 (E) and the P4 level in the culture medium (F) at vehicle (0), 3 hours, 6 hours, and 12 hours after incubating the cells with 0.1 μM E2 are shown. G, The expression of MAP3K8 was measured by RT-qPCR after incubating the cells with vehicle (0) and 0.01, 0.1, and 1 μM E2 for 6 hours. H, mRNA levels of MAP3K8 at the mid-CL at 0, 3, 6, and 12 hours after E2 was injected, as measured by RT-qPCR. I, Protein levels of MAP3K8 in the mid-CL at 0, 3, 6, and 12 hours after E2 was injected, as measured by WB. Results of one representative experiment are shown. J, Quantification of MAP3K8 protein levels at 0, 3, 6, and 12 hours after E2 was injected. K, P4 level in the serum at 0, 3, 6, and 12 hours after E2 was injected. Results are means ± SEM of three independent experiments, each conducted in triplicate and normalized to vehicle group. *, P < .05 (by t test).