Interactions Between Oestradiol 3,17ß and Progesterone on the Induction and Growth of Deciduomata in Ovariectomized Mice

The hormonal control of uterine sensitivity in progesterone-treated, ovariectomized mice was investigated by stimulating the deciduoma reaction by various means. Uterine sensitivity reached a peak on day 5 of progesterone treatment and then declined. Oestradiol before and after stimulation significantly increased the weight of the deciduomata induced by crushing, bradykinin, and compound 48/80 and increased uterine sensitivity so that intraluminal peanut oil could induce deciduomata. A single injection of 0�024 fJ-g of oestradiol 8 hr before intraluminal peanut oil also greatly increased uterine receptivity to oil. The dose of oestradiol and the time of injection of oestradiol and progesterone were critical parameters. Surprisingly, the hormonal requirements for uterine sensitivity to intraluminal peanut oil are more stringent than for transferred blastocysts.