title: Serum activin A and follistatin concentrations during human pregnancy: a cross-sectional and longitudinal study.
abstract: Activin A, a dimer of the betaA-subunit of inhibin, has been shown to have multiple biological activities and sites of production. Follistatin is a high-affinity binding protein for activin, which neutralizes its activity. This study provides the first data, using a cross-sectional design, on the measurement of both these proteins in the maternal circulation of a large cohort of women (6-39 weeks of gestation, n = 2-20 women/time point) during normal pregnancies, and confirms that similar patterns are seen in nine women studied longitudinally during pregnancy. The concentrations of total activin A were measured using a specific two-site enzyme-linked immunosorbent assay (ELISA), and a new radioimmunoassay for measuring total follistatin in serum utilizing dissociating reagents to eliminate the interference of activin is described. At 38-39 weeks gestation, both activin A and follistatin concentrations rose to a peak (4.59 +/- 0.54 ng/ml and 72.7 +/- 3.31 ng/ml, respectively). The activin A and follistatin concentrations were highly correlated both in the cross-sectional study (P <0.0001) and in individual women in the longitudinal study (P <0.05-0.0001). Concentrations of follistatin showed a greater increase in the second trimester of pregnancy relative to activin A concentrations. The parallel increase in the secretion of these two proteins throughout pregnancy probably reflects feto-placental secretion.
authors.affiliation: Institute of Reproduction and Development, Monash University, Clayton, Victoria, Australia.
authors.forename: A E
authors.initials: AE
authors.lastname: O'Connor
authors.forename: J R
authors.initials: JR
authors.lastname: McFarlane
authors.forename: S
authors.initials: S
authors.lastname: Hayward
authors.forename: T
authors.initials: T
authors.lastname: Yohkaichiya
authors.forename: N P
authors.initials: NP
authors.lastname: Groome
authors.forename: D M
authors.initials: DM
authors.lastname: de Kretser
mesh_terms: D028341:Activins; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D038681:Follistatin; D005865:Gestational Age; D006023:Glycoproteins / Q000097:blood*; D006133:Growth Substances / Q000097:blood*; D006801:Humans; D007265:Inhibins / Q000097:blood*; D008137:Longitudinal Studies; D008297:Male; D011247:Pregnancy / Q000097:blood*; D011863:Radioimmunoassay; D012016:Reference Values
chemical_list: D038681:Follistatin; D006023:Glycoproteins; D006133:Growth Substances; D028341:Activins; D007265:Inhibins