title: Identification, characterization and localization of corticotropin-releasing hormone receptors in human placenta.
abstract: The purpose of this work was to identify, characterise, and localise specific CRH binding sites in whole vaginally delivered term human placental membranes as well as in dispersed and purified trophoblastic membranes. We have found that whole placenta membranes contained specific and saturable CRH-binding sites. Maximum specific binding was obtained at pH 7.2-7.4, 22 C, for 2 h. The order of potency of CRH analogs was h/rCRH > alpha-helCRH > oCRH. Scatchard analysis revealed a single population of high affinity binding sites with a dissociation constant of 1.25 nM and maximum binding capacity of 119 fmol/mg of protein. Purified syncytiotrophoblast membranes contained high affinity CRH binding sites exhibiting the same dissociation constant and maximum binding capacity as whole placental membranes, suggesting that the CRH binding sites are expressed almost exclusively by the syncytiotrophoblast. Our findings indicate that CRH binding sites in the human placenta are exhibit similar characteristics to that described for anterior pituitary, brain and adrenals.
authors.affiliation: Department of Experimental Endocrinology, Medical School, University of Crete, Heraklion, Greece.
authors.forename: A
authors.initials: A
authors.lastname: Hatzoglou
authors.forename: A N
authors.initials: AN
authors.lastname: Margioris
authors.forename: E
authors.initials: E
authors.lastname: Bakogeorgou
authors.forename: A
authors.initials: A
authors.lastname: Gravanis
authors.forename: E
authors.initials: E
authors.lastname: Castanas
mesh_terms: D003346:Corticotropin-Releasing Hormone / Q000378:metabolism; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D010920:Placenta / Q000378:metabolism*; D011247:Pregnancy; D011485:Protein Binding; D018019:Receptors, Corticotropin-Releasing Hormone / Q000378:metabolism*; D013696:Temperature
chemical_list: D018019:Receptors, Corticotropin-Releasing Hormone; D003346:Corticotropin-Releasing Hormone