title: Inhibin expression in normal and pre-eclamptic placental tissue.
abstract: Serum inhibin levels increase during normal pregnancy, but are significantly higher in patients with pre-eclampsia. The aim of this study was to demonstrate possible increased expression of inhibin within the placentas of women with pre-eclampsia compared with non-pre-eclamptic controls. Cellular expression of inhibin alpha and beta A subunits was studied using immunohistochemistry on formalin-fixed, paraffin-embedded placental sections from cases of pre-eclampsia (n = 23) and gestational age-matched non-pre-eclamptic controls (n = 16). Immunohistochemistry was performed using monoclonal antibodies against inhibin alpha and beta A subunits by the indirect immunoperoxidase technique. Intensity of staining was graded by a semiquantitative scoring method. Differences in distribution and intensity of staining between control and pre-eclamptic placentas were analyzed using a nonparametric Mann-Whitney U test. Staining for both inhibin alpha and beta A was predominantly confined to the cytoplasm of syncytiotrophoblast, with weak expression within intermediate trophoblast. The intensity of staining for inhibin alpha was significantly greater in the syncytiotrophoblast of pre-eclamptic patients (mean staining intensity controls = 0.97, disease = 1.87; p < 0.001). Inhibin beta A staining was generally stronger than for the alpha subunit, and was also significantly increased in pre-eclamptic patients compared with controls (mean controls = 1.72, disease 2.19; p < 0.05). This is the first evidence for increased placental inhibin presence in pre-eclampsia, suggesting increased inhibin production within the placenta, a finding that could account for increased serum inhibin levels in pre-eclampsia.
authors.affiliation: Nuffield Department of Obstetrics and Gynaecology, John Radcliffe Hospital, Oxford, UK.
authors.forename: N
authors.initials: N
authors.lastname: Jackson
authors.forename: S C
authors.initials: SC
authors.lastname: Biddolph
authors.forename: W
authors.initials: W
authors.lastname: Ledger
authors.forename: N P
authors.initials: NP
authors.lastname: Groome
authors.forename: S
authors.initials: S
authors.lastname: Manek
mesh_terms: D003593:Cytoplasm / Q000737:chemistry; D003656:Decidua / Q000737:chemistry; D005260:Female; D005865:Gestational Age; D006801:Humans; D007150:Immunohistochemistry; D007265:Inhibins / Q000032:analysis*; D010920:Placenta / Q000737:chemistry*; D011225:Pre-Eclampsia / Q000378:metabolism*; D011247:Pregnancy; D014018:Tissue Distribution; D014327:Trophoblasts / Q000737:chemistry
chemical_list: D007265:Inhibins