Implantation in ovariectomized mice treated with dibutyryl adenosine 3',5'-monophosphate (dibutyryl cyclic AMP).

Experiments are described that demonstrate that uterine intraluminal injection of a 1-25 mM-solution of dibutyryl cyclic AMP (dcAMP) in phosphate buffered saline (PBS) induced implantation in ovariectomized pregnant mice. Pretreatment with progesterone was essential for this effect. When PBS was injected alone, it did not induce implantation in mice treated with progesterone. Bilateral adrenalectomy had no effect on the ability of dcAMP to substitute for oestradiol, showing that the effect was not due to dcAMP-induced oestrogen synthesis in the adrenal cortex. It is suggested that the dcAMP may act at the level of the uterus, the embryo, or both.