Fig. 2.

Estrogen shortens the period of PER2::LUC expression in the uterus of OVX mice. A–E: representative bioluminescence traces showing the effects of E₂ on circadian rhythms of PER2::LUC expression in cultured uterine explants from OVX mice. The uterus was treated with vehicle (100 μM β-cyclodextrin) or 1 nM (A), 10 nM (B), 100 nM (C), 1 μM (D), or 10 μM E₂ (E). The black trace in each graph is the same vehicle control trace. F: mean period values (±SE) for each group. Numbers in parentheses indicate the number of animals in each group. **P < 0.01 and *P < 0.05 when compared with vehicle group (Tukey's test).