title: Characterization of erythropoietin-like activity from mouse spleen cells.
abstract: Supernatants from mouse spleen cell cultures contain a factor which acts in a similar manner to erythropoietin (Ep) to stimulate the formation of 2-day erythroid (CFU-E) colonies in vitro from bone marrow or fetal liver cells. Analysis of conditioned media by high performance liquid chromatography (HPLC) on anion exchange, reverse phase, molecular size exclusion, and hydroxyapatite columns demonstrated that the erythropoietin-like activity (EpLA) has different biochemical characteristics to mouse Ep from anemic mouse serum. In addition, EpLA has a molecular weight (Mr), of 20,000 daltons determined by SDS-polyacrylamide gel electrophoresis (SDS-PAGE), compared to 42,000 for mouse Ep. Partially purified EpLA was found to be active in vivo as well as in vitro. Highly purified preparations of gamma-interferon, Multilineage hemopoietic growth factor (Multi HGF), Interleukin-2 (IL-2), IL-1, and colony stimulating factor 1 (CSF-1) did not support CFU-E colony formation. Thus, it was established that EpLA could not be attributed to other known components of spleen cell conditioned medium. Titration of mouse Ep and EpLA suggests that only a portion of the Ep-responsive CFU-E population in fetal liver is sensitive to EpLA.
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid; D003115:Colony-Stimulating Factors / Q000032:analysis; D017886:Durapatite; D004591:Electrophoresis, Polyacrylamide Gel; D004921:Erythropoietin / Q000032:analysis* / Q000494:pharmacology; D006133:Growth Substances / Q000032:analysis; D016298:Hematopoietic Cell Growth Factors; D006412:Hematopoietic Stem Cells / Q000187:drug effects; D006882:Hydroxyapatites; D007371:Interferon-gamma / Q000032:analysis; D051379:Mice; D008970:Molecular Weight; D013154:Spleen / Q000032:analysis*
chemical_list: D003115:Colony-Stimulating Factors; D006133:Growth Substances; D016298:Hematopoietic Cell Growth Factors; D006882:Hydroxyapatites; D004921:Erythropoietin; D007371:Interferon-gamma; D017886:Durapatite