Effect of 5-fluorouracil on "primitive" hematopoietic stem cells that reconstitute whole erythropoiesis of genetically anemic W/Wv mice.

The potential to reconstitute the whole erythropoiesis of a genetically anemic (WB X C57BL/6)F1-W/Wv (WBB6F1-W/Wv) mouse for at least 8 weeks was compared between 5-fluorouracil (5FU)-treated and nontreated bone marrow cells. C57BL/6-Pgk-1b/Pgk-1a female mice, in which each stem cell had either A-type or B-type phosphoglycerate kinase (PGK) owing to the random inactivation of one of two X chromosomes, were used as donors. As a marker of the reconstitution, electrophoretic pattern of hemoglobin was used. The concentration of the stem cells that reconstitute the whole erythropoiesis of WBB6F1-W/Wv mouse was higher in the marrow of donors that had received an injection of 5FU two days previously (two-day 5FU-treated) than in the marrow of nontreated donors. In the marrow of four-day 5FU-treated mice, however, the concentration was comparable to that of nontreated mice. The PGK electrophoretic pattern of WBB6F1-W/Wv mice reconstituted by nontreated marrow cells was comparable to the PGK pattern of WBB6F1-W/Wv mice reconstituted by four-day 5FU-treated marrow cells. Thus, a single stem cell with extensive proliferative potential rather than multiple spleen colony-forming units appeared to be responsible for the erythropoietic reconstitution in the transplantation of nontreated healthy marrow cells as well as 5FU-treated marrow cells.