title: Expression of the parathyroid Ca(2+)-sensing receptor in cytotrophoblasts from human term placenta.
abstract: Fura-2-loaded human cytotrophoblasts responded to elevated extracellular Ca2+ concentration ([Ca2+]o) with monophasic or, in the case of large (> 20 microns) extravillous cells, biphasic elevations in intracellular free Ca2+ ion concentration ([Ca2+]i) that returned to baseline levels after restoration of control [Ca2+]o. Large extravillous cytotrophoblasts also responded to elevated [Mg2+]o with transient elevations in [Ca2+]i, consistent with the behaviour of the parathyroid Ca2(+)-sensing receptor. Expression of the parathyroid Ca2(+)-sensing receptor in placental cells was confirmed using Northern blot and reverse transcription (RT)-PCR analysis. However, the major transcript in human placental cells (6.2 kb) differed from that expressed by human parathyroid cells (5.6 kb). RT-PCR analysis and DNA sequencing of key PCR products also revealed the presence of a splice variant in placental and parathyroid cells that lacks exon 3.
authors.affiliation: Department of Biochemistry, University of Sydney, New South Wales, Australia.
authors.forename: R A
authors.initials: RA
authors.lastname: Bradbury
authors.forename: K L
authors.initials: KL
authors.lastname: Sunn
authors.forename: M
authors.initials: M
authors.lastname: Crossley
authors.forename: M
authors.initials: M
authors.lastname: Bai
authors.forename: E M
authors.initials: EM
authors.lastname: Brown
authors.forename: L
authors.initials: L
authors.lastname: Delbridge
authors.forename: A D
authors.initials: AD
authors.lastname: Conigrave
mesh_terms: D015152:Blotting, Northern; D005091:Exons; D005260:Female; D006801:Humans; D016133:Polymerase Chain Reaction; D011247:Pregnancy; D012333:RNA, Messenger / Q000032:analysis*; D044169:Receptors, Calcium-Sensing; D011956:Receptors, Cell Surface / Q000235:genetics*; D017422:Sequence Analysis, DNA; D014327:Trophoblasts / Q000378:metabolism*
chemical_list: D012333:RNA, Messenger; D044169:Receptors, Calcium-Sensing; D011956:Receptors, Cell Surface