Wolfahrt, S.S.WolfahrtKleine, B.B.KleineJarry, HubertusHubertusJarryRossmanith, W. G.W. G.Rossmanith2018-11-072018-11-072001https://resolver.sub.uni-goettingen.de/purl?gro-2/32689Gonadotrophin releasing hormone (GnRH) plays an important regulatory role in the function and growth of human placenta, but its placental expression sites and co-localization with GnRH receptor (GnRH-R) are not well known, GnRH and GnRH-R expression has been found in both placenta and cultured trophoblasts; however, cultured trophoblastic cells very quickly lose GnRH-R message and subsequently receptor protein. Speculating that endogenously released GnRH induced this down-regulation, we determined GnRH-R in cultures of trophoblastic cells in the presence of a neutralizing anti-GnRH antibody, Cells incubated with this antibody showed a strong signal for the GnRH-R, while those cultured without did not las analysed by immunofluorescence, reverse transcription-polymerase chain reaction, protein 'dot blot' and Western blotting), Furthermore, addition of the GnRH agonist buserelin led to a reduction of the receptor protein. We have therefore shown that GnRH released from trophoblastic cells down-regulates GnRH-R in these trophoblastic cells. Having previously shown that trophoblast layers were synchronously positive for GnRH and GnRH-R, these new findings support the hypothesis of an ultrashort feedback regulation of trophoblasts by GnRH involving autocrine regulation of GnRH-R.journal_article10.1093/molehr/7.1.8911134365000166460800013