title: Placental alkaline phosphatase expression at the apical and basal plasma membrane in term villous trophoblasts.
abstract: Human placental alkaline phosphatase (PLAP) was localized at the apical and basal plasma membrane of syncytiotrophoblasts and at the surface of cytotrophoblasts in term chorionic villi using immunoelectron microscopy. Similarly, apical and basolateral PLAP expression was found in polarized trophoblast-derived BeWo cells. Trophoblasts isolated from term placentas exhibited mainly vesicular PLAP immunofluorescence staining immediately after isolation. After in vitro differentiation into syncytia, PLAP plasma membrane expression was upregulated and exceeded that observed in mononuclear trophoblasts. These data call for caution in using PLAP as a morphological marker to differentiate syncytiotrophoblasts from cytotrophoblasts or as a marker enzyme for placental brush-border membranes. (J Histochem Cytochem 49:1155-1164, 2001)
authors.affiliation: Department of Pathophysiology, University of Vienna, Vienna, Austria.
authors.forename: K
authors.initials: K
authors.lastname: Leitner
authors.forename: R
authors.initials: R
authors.lastname: Szlauer
authors.forename: I
authors.initials: I
authors.lastname: Ellinger
authors.forename: A
authors.initials: A
authors.lastname: Ellinger
authors.forename: K P
authors.initials: KP
authors.lastname: Zimmer
authors.forename: R
authors.initials: R
authors.lastname: Fuchs
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism*; D002462:Cell Membrane / Q000201:enzymology; D016764:Cell Polarity; D002478:Cells, Cultured; D002824:Chorionic Villi / Q000201:enzymology; D020285:Cryoelectron Microscopy; D005455:Fluorescent Antibody Technique; D015726:Giant Cells / Q000166:cytology / Q000201:enzymology; D006801:Humans; D010920:Placenta / Q000166:cytology / Q000201:enzymology* / Q000648:ultrastructure; D014327:Trophoblasts / Q000201:enzymology; D015854:Up-Regulation
chemical_list: D000469:Alkaline Phosphatase