Evidence of prostaglandin involvement in blastocyst implantation.

Delayed-implantation mice were used to test for local implantation induction effects of prostaglandins E2 and F2 alpha. Evidence of implantation was gathered by microdissection of implantation sites and by scanning electron microscopy. Indomethacin was tested for the ability to interfere with the mechanisms of estrogen-induced, normal implantation. Both prostaglandins appear to have significant effect inducing implantation when applied locally in the uterine lumen, PGE2 being more effective than PGF2 alpha. The indomethacin clearly has a blocking effect on normal implantation. However, indomethacin appears only partially able to prevent the morphological changes indicative of the trophoblast cell transformation.