In vivo erythropoietin requirements of regenerating erythroid progenitors
(BFU-e, CFU-e) in bone marrow of mice
KB Udupa and KR Reissmann
Erythroid progenitors (B-8, B-4, CFU-e) in the femoral marrow of
polycythemic mice were measured by in vitro culture assays after a single
administration of BCNU or Myleran. BCNU reduced pluripotent stem cells to
40% and erythroid progenitors to less than 5% of normal. B-8, the earliest
erythroid progenitors, regenerated without erythropoietin (Epo) completely
within 5 days. At 14 days after BCNU, intermediate progenitors (B-4)
attained 60% of their normal numbers and CFU-e attained approximately 30%.
Daily injections of Epo promptly restored normal B-4 numbers and
near-normal CFU-e numbers in BCNU-treated mice. After Myleran, CFU-s
remained below 2% of normal for 14 days, and no regeneration of the B-8
occurred with or without daily Epo injections. The findings suggest that
regneration of B-8 was dependent on cell inflow from the pluripotent stem
cell compartment but was independent of the presence of Epo. Intermediate
progenitors (B-4) required Epo and the presence of B-8 for complete and
permanent regeneration. CFU-e were the most Epo-dependent of the three
progenitors. B-4, recruited by Epo, required after their formation a second
exposure to the hormone in order to progress into the CFU-e stage.
Volume 53,
Issue 6,
pp. 1164-1171,
06/01/1979
Copyright © 1979 by The American Society of Hematology
