title: Competitive protein binding assay for activin A/EDF using follistatin determination of activin levels in human plasma.
abstract: A sensitive and specific protein binding assay for activin A/EDF (activin) was developed using follistatin as a binding protein and [125I] labelled activin as a tracer. As 50% acetonitrile (CH3CN) separated free and follistatin-bound activin, plasma pretreated with an equal volume of CH3CN was used as the assay sample and B/F separation was also done with 50% CH3CN. The recovery of the assay was 85.0% and its sensitivity was 0.5 ng/ml. Crossreactivity with inhibin A was 1.8%. The mean plasma level of follistatin-free activin in normal subjects was 1.3 +/- 0.7%. (M +/- SD) ng/ml. Plasma free activin levels were generally elevated in patients with chronic renal failure or hematological diseases associated with anemia.
authors.affiliation: Radioassay Center, Tokyo Women's Medical College, Japan.
authors.forename: R
authors.initials: R
authors.lastname: Demura
authors.forename: T
authors.initials: T
authors.lastname: Suzuki
authors.forename: S
authors.initials: S
authors.lastname: Tajima
authors.forename: S
authors.initials: S
authors.lastname: Mitsuhashi
authors.forename: E
authors.initials: E
authors.lastname: Odagiri
authors.forename: Y
authors.initials: Y
authors.lastname: Eto
authors.forename: H
authors.initials: H
authors.lastname: Sugino
authors.forename: H
authors.initials: H
authors.lastname: Demura
mesh_terms: D028341:Activins; D000328:Adult; D000368:Aged; D000818:Animals; D005260:Female; D005498:Follicular Phase; D038681:Follistatin; D006023:Glycoproteins / Q000378:metabolism*; D006133:Growth Substances / Q000097:blood; D006402:Hematologic Diseases / Q000097:blood*; D006801:Humans; D007265:Inhibins / Q000097:blood*; D007457:Iodine Radioisotopes; D007676:Kidney Failure, Chronic / Q000097:blood*; D007938:Leukemia / Q000097:blood; D008183:Luteal Phase; D008297:Male; D008593:Menopause; D008875:Middle Aged; D011869:Radioligand Assay; D011994:Recombinant Proteins / Q000032:analysis; D012016:Reference Values; D013552:Swine
chemical_list: D038681:Follistatin; D006023:Glycoproteins; D006133:Growth Substances; D007457:Iodine Radioisotopes; D011994:Recombinant Proteins; D028341:Activins; D007265:Inhibins