title: Regulation of placental transfer: the Na(+)/H(+) exchanger--a review.
abstract: This review article considers the purposes and mechanisms of regulation of placental transfer in general terms and then illustrates some key points with reference to the Na(+)/H(+) exchanger (NHE), a transport protein found in the syncytiotrophoblast. NHE probably has a role in the homeostasis of syncytiotrophoblast intracellular pH and may also be involved in syncytiotrophoblast cell volume regulation as well as H(+) loss from and Na(+) transfer to the fetus. The activity and expression of NHE in the microvillous plasma membrane of the syncytiotrophoblast is reduced in placentas from preterm, growth restricted babies as compared to their gestationally matched normally grown counterparts. There are differential effects of gestation in normal pregnancy on NHE mRNA, NHE protein and NHE activity. There is also evidence of acute modulation of NHE activity. Regulation of NHE in syncytiotrophoblast is therefore complex with control at transcription, post transcription and post translational loci.
authors.affiliation: Academic Unit of Child Health, University of Manchester, St. Mary's Hospital, Manchester, M13 0JH, UK. colin.sibley@man.ac.uk
authors.forename: C P
authors.initials: CP
authors.lastname: Sibley
authors.forename: J D
authors.initials: JD
authors.lastname: Glazier
authors.forename: S L
authors.initials: SL
authors.lastname: Greenwood
authors.forename: H
authors.initials: H
authors.lastname: Lacey
authors.forename: K
authors.initials: K
authors.lastname: Mynett
authors.forename: P
authors.initials: P
authors.lastname: Speake
authors.forename: T
authors.initials: T
authors.lastname: Jansson
authors.forename: M
authors.initials: M
authors.lastname: Johansson
authors.forename: T L
authors.initials: TL
authors.lastname: Powell
mesh_terms: D000328:Adult; D001692:Biological Transport; D005260:Female; D005317:Fetal Growth Retardation / Q000503:physiopathology; D006801:Humans; D010920:Placenta / Q000378:metabolism*; D011247:Pregnancy; D012333:RNA, Messenger / Q000378:metabolism; D015398:Signal Transduction; D017923:Sodium-Hydrogen Exchangers / Q000235:genetics / Q000378:metabolism*; D014327:Trophoblasts / Q000378:metabolism
chemical_list: D012333:RNA, Messenger; D017923:Sodium-Hydrogen Exchangers