Repetitive mobilization of normal hematopoietic stem cells and APL blasts into the peripheral blood. Syngeneic B6129F1 recipient mice were left untreated (nonleukemic) or injected intravenously with 106 APL cells (leukemic). Twelve days after APL injection, mice were treated with a single subcutaneous dose of 5 mg/kg AMD3100 for 5 consecutive days. Peripheral blood samples were collected immediately before (pre-AMD3100) and 3 hours after (post-AMD3100) each daily dose of AMD3100. (A,C) Total white blood cell counts per microliter of peripheral blood in nonleukemic (A) and leukemic (C) mice. (C) Colony-forming units in the peripheral blood of nonleukemic mice. (D) Blast cell counts per microliter of peripheral blood in leukemic mice. APL blast cell counts per microliter of peripheral blood in leukemic mice were determined by automated counting and flow cytometry of Gr1+CD34+ APL blast cells. Each bar represents the mean ± SD of a single experiment, for which each sample was assayed in triplicate. *P < .05; **P < .01; and ***P < .001.
