Identity of Erythroblast Precursors in Bone Marrow

Reticulocyte Generation Time and Rate of Discharge from the Marrow

“…The non-significant increase in more mature forms of marrow reticulocytes on day 1 %-2 y2 probably reflected the maturation of the few remaining erythroblasts [7]. The significant increase in the youngest forms from day 2 y2 to day 3 on the other hand, must represent the cells that started their maturation from the erythroid precursor cell.…”

“…In unstimulated animals the abrupt increase in blood reticulocytes was preceded by the return of the red cell count to the range of normal. Although the peripheral reticulocytosis was heralded by the reappearance of erythroblasts [7], restoration of the marrow reticulocyte reserve to the normal level did not take place. In stimulated animals, however, in contrast to the controls, a highly significant accumulation of reticulocytes within the marrow paralleled the rise in blood reticulocytes.…”