title: Assays for endogenous components of human milk: comparison of fresh and frozen samples and corresponding analytes in serum.
abstract: Breast milk is a primary source of nutrition that contains many endogenous compounds that may affect infant development. The goals of this study were to develop reliable assays for selected endogenous breast milk components and to compare levels of those in milk and serum collected from the same mother twice during lactation (2-7 weeks and 3-4 months). Reliable assays were developed for glucose, secretory IgA, interleukin-6, tumor necrosis factor-a, triglycerides, prolactin, and estradiol from participants in a US EPA study called Methods Advancement in Milk Analysis (MAMA). Fresh and frozen (-20 degrees C) milk samples were assayed to determine effects of storage on endogenous analytes. The source effect (serum vs milk) seen in all 7 analytes indicates that serum should not be used as a surrogate for milk in children's health studies. The authors propose to use these assays in studies to examine relationships between the levels of milk components and children's health.
authors.affiliation: Reproductive Toxicology Division, US Environmental Protection Agency, Research Triangle Park, NC, USA.
authors.forename: Erin P
authors.initials: EP
authors.lastname: Hines
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Rayner
authors.forename: Randy
authors.initials: R
authors.lastname: Barbee
authors.forename: Rae Ann
authors.initials: RA
authors.lastname: Moreland
authors.forename: Andre
authors.initials: A
authors.lastname: Valcour
authors.forename: Judith E
authors.initials: JE
authors.lastname: Schmid
authors.forename: Suzanne E
authors.initials: SE
authors.lastname: Fenton
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000032:analysis / Q000097:blood; D004958:Estradiol / Q000032:analysis / Q000097:blood; D005260:Female; D005615:Freezing; D005947:Glucose / Q000032:analysis; D006801:Humans; D007070:Immunoglobulin A / Q000032:analysis / Q000097:blood; D015850:Interleukin-6 / Q000032:analysis / Q000097:blood; D008895:Milk, Human / Q000737:chemistry* / Q000276:immunology*; D011388:Prolactin / Q000032:analysis / Q000097:blood; D013048:Specimen Handling / Q000009:adverse effects / Q000379:methods*; D013997:Time Factors; D014280:Triglycerides / Q000032:analysis / Q000097:blood; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis / Q000097:blood
chemical_list: D015415:Biomarkers; D007070:Immunoglobulin A; D015850:Interleukin-6; D014280:Triglycerides; D014409:Tumor Necrosis Factor-alpha; D004958:Estradiol; D011388:Prolactin; D005947:Glucose