title: Placental leukotriene B4 release in early pregnancy and in term and preterm labour.
abstract: The production of leukotriene B4 (LTB4) by the human placenta in vitro was measured by radioimmunoassay. In early pregnancy (7-12 weeks gestation) LTB4 production rate (pmol/mg dry weight/2 h) was 3.7 (2.6-4.7) (median and range; n = 9) and at term it was 0.7 (0.4-2.3; n = 10) in placental tissue obtained at elective caesarean section, and 2.7 (1.3-3.6; n = 10) in samples following labour of spontaneous onset and vaginal delivery. In spontaneous preterm labour (26-36 weeks gestation) with normal placental histology LTB4 production was 0.7 (0.3-1.7; n = 14), but it was significantly higher in preterm placentas with inflammatory infiltration: 3.1 (0.8-4.8; n = 6). These data show that the production of LTB4 by human placenta is high in early pregnancy, but remains low during the third trimester, with a significant increase in spontaneous labour at term. LTB4 output is low in uncomplicated preterm labour but markedly increased in chorioamnionitis-associated preterm labour.
authors.affiliation: University of Oxford, Nuffield Department of Obstetrics and Gynaecology, U.K.
authors.forename: A
authors.initials: A
authors.lastname: López Bernal
authors.forename: D J
authors.initials: DJ
authors.lastname: Hansell
authors.forename: T Y
authors.initials: TY
authors.lastname: Khong
authors.forename: J W
authors.initials: JW
authors.lastname: Keeling
authors.forename: A C
authors.initials: AC
authors.lastname: Turnbull
mesh_terms: D000293:Adolescent; D000328:Adult; D002821:Chorioamnionitis / Q000378:metabolism; D005260:Female; D006801:Humans; D007975:Leukotriene B4 / Q000096:biosynthesis*; D007752:Obstetric Labor, Premature / Q000378:metabolism*; D010920:Placenta / Q000378:metabolism*; D011247:Pregnancy; D011261:Pregnancy Trimester, First / Q000378:metabolism*; D011263:Pregnancy Trimester, Third
chemical_list: D007975:Leukotriene B4