17 beta-estradiol modulates prostaglandin E-2 release from human amnion-derived WISH cells

in human amnion-derived WISH cells [H-3]estradiol-17 beta binding sites are not detectable, but they become measurable in cells exposed to cAMP elevat ing agents such as forskolin or Ro 20-1724. In cells unexposed to these dru gs, 17 beta -estradiol stimulates prostaglandin (PG)E-2 release but exerts an evident inhibitory effect in cells exposed to Ro 20-1724, Both stimulato ry and inhibitory actions are inhibited by the estrogen receptor antagonist , tamoxifen, by cell pretreatment with cycloheximide, or when the hormone i s bound to BSA. Our data demonstrate for the first time that 1) 17 beta -es tradiol modulates PGE(2) release from WISH cells, interacting with specific intracellular receptors and probably evoking new protein synthesis, and 2) WISH cell responsiveness to 17 beta -estradiol seems to be modulated by cA MP, whose levels are significantly increased by the steroid hormone in the presence of Ro 20-1724. The nucleotide is presumably responsible for the en hacement of hormone receptor availability and for the inhibition of PGE(2) release observed in the presence of Ro 20-1724.