title: Identification of activin A and follistatin in human milk.
abstract: Activin A is a dimeric protein member of the transforming growth factor-beta (TGF-beta) family: it is synthesized by a variety of organs and follistatin is an activin-binding protein. A sensitive and specific assays for bioactive dimeric activin A and follistatin have recently allowed to measure these proteins in blood and other biological fluids, giving a new insights into their possible physiological role. Since human breast is able to produce activin A, the aim of the present study was to evaluate whether it and follistatin are measurable in breast milk of women during lactation. Concentrations of activin A and follistatin were measured in milk samples collected at 3, 5 and 30 days after delivery by using specific and sensitive two-site ELISAs. For the first time the presence of immunoreactive activin A and follistatin in human milk has been shown; no significant different concentration between the third and the fifth day after delivery was found. Furthermore, no difference of activin A and follistatin concentration between the whole and the skim milk or between spontaneous delivery and cesarean section was found. Milk activin A and follistatin concentrations after 1 month of lactation were significantly decreased (P < 0.01). Activin A and follistatin are present in human milk in high concentrations in the first week of lactation, while decrease after a month suggesting a possible role as growth factors in human milk.
authors.affiliation: Chair of Obstetrics and Gynecology, Department of Pediatrics, Obstetrics and Reproductive Medicine, University of Siena, Policlinico Le Scotte, Viale Bracci, 53100 Siena, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Luisi
authors.forename: Giulia
authors.initials: G
authors.lastname: Calonaci
authors.forename: Pasquale
authors.initials: P
authors.lastname: Florio
authors.forename: Ilaria
authors.initials: I
authors.lastname: Lombardi
authors.forename: Claudio
authors.initials: C
authors.lastname: De Felice
authors.forename: Franco
authors.initials: F
authors.lastname: Bagnoli
authors.forename: Felice
authors.initials: F
authors.lastname: Petraglia
mesh_terms: D028341:Activins / Q000378:metabolism*; D000328:Adult; D019281:Dimerization; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D038681:Follistatin / Q000378:metabolism*; D006801:Humans; D028322:Inhibin-beta Subunits / Q000378:metabolism*; D008895:Milk, Human / Q000378:metabolism*; D011247:Pregnancy; D013997:Time Factors; D016212:Transforming Growth Factor beta / Q000378:metabolism
chemical_list: D038681:Follistatin; D016212:Transforming Growth Factor beta; C422405:activin A; D028341:Activins; D028322:Inhibin-beta Subunits