title: Placental endothelial nitric oxide synthase in multiple and single dose betamethasone exposed pregnancies.
abstract: OBJECTIVE
  To compare endothelial nitric oxide synthase expression and capillary density (CDS) in placentas exposed to single or multiple courses of betamethasone.
  
  
  METHODS
  Placental specimens exposed to single vs repeat courses of betamethasone were analyzed through immunohistochemistry and digital image quantification for endothelial nitric oxide synthase and CD34. Quantified endothelial nitric oxide synthase staining, calculated capillary density, ratio of endothelial nitric oxide synthase to capillary density, and clinical characteristics were compared. Linear regression was performed with these as dependent variables.
  
  
  RESULTS
  Mean and maximum capillary density were increased (P = .013 and .005) and the ratio of endothelial nitric oxide synthase to capillary density decreased (P = .016) in specimens exposed to 4 courses of betamethasone compared with 1 to 3 courses. Exposure to 4 courses of betamethasone was associated with increased capillary density, but not with endothelial nitric oxide synthase expression.
  
  
  CONCLUSIONS
  Exposure to 4 courses of betamethasone is associated with increased placental capillary density. The placental effects of multiple courses of betamethasone are unrelated to endothelial nitric oxide synthase expression.
authors.affiliation: Departments of Obstetrics and Gynecology, Wake Forest Health Sciences, Winston-Salem, NC, USA.
authors.forename: Heather L
authors.initials: HL
authors.lastname: Mertz
authors.forename: Lisa
authors.initials: L
authors.lastname: Mele
authors.forename: Catherine Y
authors.initials: CY
authors.lastname: Spong
authors.forename: Donald J
authors.initials: DJ
authors.lastname: Dudley
authors.forename: Ronald J
authors.initials: RJ
authors.lastname: Wapner
authors.forename: Jay D
authors.initials: JD
authors.lastname: Iams
authors.forename: Yoram
authors.initials: Y
authors.lastname: Sorokin
authors.forename: Alan
authors.initials: A
authors.lastname: Peaceman
authors.forename: Kenneth J
authors.initials: KJ
authors.lastname: Leveno
authors.forename: Steve N
authors.initials: SN
authors.lastname: Caritis
authors.forename: Menachem
authors.initials: M
authors.lastname: Miodovnik
authors.forename: Brian M
authors.initials: BM
authors.lastname: Mercer
authors.forename: John M
authors.initials: JM
authors.lastname: Thorp
authors.forename: Mary J
authors.initials: MJ
authors.lastname: O'Sullivan
authors.forename: Susan M
authors.initials: SM
authors.lastname: Ramin
authors.forename: Marshall
authors.initials: M
authors.lastname: Carpenter
authors.forename: Dwight J
authors.initials: DJ
authors.lastname: Rouse
authors.forename: Baha
authors.initials: B
authors.lastname: Sibai
mesh_terms: D000328:Adult; D001623:Betamethasone / Q000008:administration & dosage*; D005260:Female; D005938:Glucocorticoids / Q000008:administration & dosage*; D006801:Humans; D066298:In Vitro Techniques; D052250:Nitric Oxide Synthase Type III / Q000096:biosynthesis*; D010920:Placenta / Q000187:drug effects* / Q000201:enzymology*; D011247:Pregnancy
chemical_list: D005938:Glucocorticoids; D001623:Betamethasone; D052250:Nitric Oxide Synthase Type III