Cyclic AMP and the preparation of the mouse uterus for implantation

Experiments are described that demonstrate the ability of dibutyryl cyclic AMP (dcAMP) to induced oestrogen-like changes in the uteri of ovariectomized mice treated with progesterone. A single intraluminal injection of 6-14 micrograms dcAMP in 0-02 ml phosphate-buffered saline promoted cell division in the uterine stroma and sensitized the endometrium so that a decidual reaction could be induced by a subsequent injection of arachis oil into the uterine lumen. Since dcAMP has already been shown to induce implantation of diapausing mouse blastocysts in the absence of oestrogen, it is suggested that cyclic AMP is involved in egg implantation in rodents.