Tamoxifen inhibition of an in vitro oestradiol-induced surface coat change on mouse blastocysts

1. Eighty-nine hour post-coitus mouse blastocysts cultured in the presence of oestradiol-17beta underwent a histochemically detectable surface coat change. 2. Tamoxifen was found to inhibit this in vitro-induced change. The role of Tamoxifen as an inhibitor of implantation is discussed.