Erythropoietin receptors on murine erythroid colony-forming units: natural history

Erythropoietin receptors on murine erythroid colony-forming units: natural history.

Erythropoietin (Epo) response and binding was assessed in purified murine CFU-E and their descendants. Several features emerged. First, Epo on CFU-E is in rapid flux: Half-time for 125I-Epo internalization is approximately four to five minutes. Second, computer-aided Scatchard analyses indicate that greater than 70 high-affinity Epo-receptor sites on anemic animal CFU-E are sometimes already oc...

Onset of erythropoietin response in murine erythroid colony-forming units: assignment to early S-phase in a specific cell generation.

Murine erythroid colony-forming units (CFU-E) representing successive cell generations in a six-generation long in vitro maturation sequence were tested for their response to erythropoietin (Epo) by measurement of Epo-exposure times necessary to stimulate heme biosynthesis. Generation I CFU-E, which produce mainly 32-cell erythroid colonies, were isolated in 82% average purity from spleens of t...

Effect of erythropoietin on proliferation of erythroid stem cells in the absence of transplantable colony-forming units.

Inhibition of human erythroid colony-forming units by gamma interferon can be corrected by recombinant human erythropoietin.

Tumor necrosis factor (TNF), interleukin-1 (IL-1), and gamma interferon (gamma IFN) inhibit erythropoiesis in vivo and in vitro, and have been implicated in the pathogenesis of the anemia of chronic disease. Anemia in patients with rheumatoid arthritis and in animals exposed chronically to IL-1 and TNF can be corrected by the administration of recombinant erythropoietin (Epo). We exposed highly...

Roles of erythropoietin, insulin-like growth factor 1, and unidentified serum factors in promoting maturation of purified murine erythroid colony-forming units.

We have used 75% to 90% pure murine erythroid colony-forming units (CFU-E) to delineate the processes and factors underlying their maturation. These CFU-E form 32 cell colonies and are drawn from what we term generation I of a six-generation long maturation sequence (Landschulz et al, Blood 79:2749, 1992). Applying assays of 59Fe-heme biosynthesis and colony numbers as measures of maturation an...