title: Mutual inhibition of murine erythropoiesis and granulopoiesis during combined erythropoietin, granulocyte colony-stimulating factor, and stem cell factor administration: in vivo interactions and dose-response surfaces.
abstract: We investigated the in vivo effects of erythropoietin (EPO) on granulopoiesis and, conversely, the effect of granulocyte colony-stimulating factor (G-CSF) treatment on erythropoiesis. Recombinant human EPO at four different doses in combination with recombinant human G-CSF also at four different doses was simultaneously administered for 7 days to splenectomized mice. In total, 16 different combinations of growth factors were thus tested. G-CSF administration increased granulocyte production as expected, whereas immature colony-forming unit granulocyte-macrophage numbers were decreased. EPO analogously increased late erythroid cell numbers. Both EPO and G-CSF dose-dependently inhibited late cell stages of the opposite lineage, with EPO abrogating G-CSF-stimulated granulopoiesis and, conversely, G-CSF inhibiting EPO-stimulated erythropoiesis. In a subsequent experiment, we tested whether these lineage-competitive effects could be prevented by coadministering stem cell factor (SCF). In these three factor-treated mice, all granuloid and erythroid cell stages increased, thereby reducing the effect of the mutual inhibition. We conclude that EPO-stimulated erythropoiesis and G-CSF-stimulated granulopoiesis inhibited each other at a late level. Simultaneous SCF administration increased the input into both the erythroid and granuloid compartment and thereby compensated the mutual inhibition. This study shows that intricate dose-response relationships exist between various growth factors that should be carefully analyzed before combinations of these factors are used in humans.
authors.affiliation: Groningen Institute for Drug Studies, Department of Hematology, University of Groningen, The Netherlands.
authors.forename: G
authors.initials: G
authors.lastname: de Haan
authors.forename: C
authors.initials: C
authors.lastname: Engel
authors.forename: B
authors.initials: B
authors.lastname: Dontje
authors.forename: W
authors.initials: W
authors.lastname: Nijhof
authors.forename: M
authors.initials: M
authors.lastname: Loeffler
mesh_terms: D000818:Animals; D004305:Dose-Response Relationship, Drug; D004336:Drug Antagonism; D004920:Erythropoiesis / Q000187:drug effects; D004921:Erythropoietin / Q000494:pharmacology*; D016179:Granulocyte Colony-Stimulating Factor / Q000494:pharmacology*; D006098:Granulocytes; D006410:Hematopoiesis / Q000187:drug effects*; D016298:Hematopoietic Cell Growth Factors / Q000494:pharmacology*; D051379:Mice; D008810:Mice, Inbred C57BL; D011994:Recombinant Proteins / Q000494:pharmacology; D012044:Regression Analysis; D013156:Splenectomy; D019089:Stem Cell Factor
chemical_list: D016298:Hematopoietic Cell Growth Factors; D011994:Recombinant Proteins; D019089:Stem Cell Factor; D004921:Erythropoietin; D016179:Granulocyte Colony-Stimulating Factor