Figure 1.

Schematic diagram for the five (I—V) treatment protocols administered to ovariectomized (Ovx) C57Bl/6 (B6) mice. Hormones were dissolved in sesame oil and given from the sixth day after ovariectomy (0.05ml, once/day, subcutaneously). All mice were sacrificed 24 hrs after their last treatment (†). For groups I-III, injections of different compounds were given on 3 consecutive days. For the combination treatments, the protocols were identical to day 14. In group IV, where the uterus was not decidualized, euthanasia was at day 15. In group V, where an artificial decidua was induced, P4 treatment was extended for a further 72 hr and the uteri of anaesthetized mice were stimulated 48 hr into the extended treatment interval using an intralumenal injection of 10 μl sterile sesame seed oil.