title: Reticulocyte measurements as a bioassay for erythropoietin.
abstract: The possibility of using reticulocyte counts in peripheral blood to assay erythropoietic activity of recombinant human erythropoietin (r-HuEPO) was evaluated in normal mice. Mice were injected subcutaneously with r-HuEPO on days 0, 1 and 2 and bled on day 4 for reticulocyte count determinations, using an automated counting system with thiazole orange fluorescent staining and flow cytometric analysis. Reticulocyte counts increased in a dose-dependent fashion upon administration of r-HuEPO. The reticulocyte count was unaffected by asialylated EPO as well as other substances tested (interleukin-1, interleukin-3, dexamethasone, human chorionic gonadotropin). These data demonstrate the usefulness of employing reticulocyte counts as a rapid, specific and reproducible assay for in vivo erythropoietic activity of r-HuEPO.
authors.affiliation: R.W. Johnson Pharmaceutical Research Institute, Raritan, NJ 08869.
authors.forename: A G
authors.initials: AG
authors.lastname: Barbone
authors.forename: B
authors.initials: B
authors.lastname: Aparicio
authors.forename: D W
authors.initials: DW
authors.lastname: Anderson
authors.forename: J
authors.initials: J
authors.lastname: Natarajan
authors.forename: D M
authors.initials: DM
authors.lastname: Ritchie
mesh_terms: D000818:Animals; D001681:Biological Assay; D004305:Dose-Response Relationship, Drug; D004921:Erythropoietin / Q000494:pharmacology*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007202:Indicators and Reagents; D051379:Mice; D011086:Polycythemia / Q000097:blood; D011994:Recombinant Proteins / Q000494:pharmacology; D017701:Reticulocyte Count / Q000187:drug effects*
chemical_list: D007202:Indicators and Reagents; D011994:Recombinant Proteins; D004921:Erythropoietin