Figure 4.

The response to LH stimulation is impaired in GCs of Epab^−/− mice. A–D, Western blot analysis was performed to compare LH-induced phosphorylation of MEK1/2, ERK1/2, and p90RSK in GCs from WT and Epab^−/− mice. GCs were collected from WT and Epab^−/− mice at 12 weeks of age 44–48 hours after 5-IU PMSG injection, cultured, serum starved, and treated with LH (1 μg/mL) for 5 and 10 minutes. Representative Western blottings of total (T) and phosphorylated (p) proteins are shown in A. The intensity of Western blot bands was analyzed using densitometry. The ratio of p-MEK1/2 (B), p-ERK1/2 (C), and p-p90RSK (D) to total protein was normalized to untreated WT control. Data are presented as mean ± SEM from 3 separate experiments. *, significant difference between groups (*, P < .05; **, P < .01; ***, P < .001). Significance was determined by two-way ANOVA followed by Tukey's multiple comparisons test.