Cell cycle status of murine megakaryocyte and granulocyte-macrophage colony-forming cells in bone marrow and spleen.
The cell cycle status of megakaryocyte colony-forming cells (Meg-CFC) and granulocyte-macrophage colony-forming cells (GM-CFC) from the spleen and bone marrow of C57BL mice was evaluated by determining the effects of hydroxyurea (OHU) or cytosine arabinoside (Ara-C), both in vivo and in vitro, upon colony-forming cells (CFC). The concentrations of cells in culture (2 x 10(6) to 4 x 10(6)/ml for spleen and 0.25 x 10(5) to 1.0 x 10(5)/ml for bone marrow) did not alter cell cycle status of either Meg-CFC or GM-CFC. Determination of cell cycle status following in vivo administration of OHU indicated that 25.2% of Meg-CFC and 28.1% of GM-CFC in the spleen, and 26.0% of Meg-CFC and 29.5% of GM-CFC in the bone marrow, were in cycle. In vitro incubation of CFC with OHU showed that in the spleen 25.1% of Meg-CFC and 24.2% of GM-CFC were engaged in DNA synthesis, whereas in bone marrow 28.5% of Meg-CFC and 29.2% of GM-CFC were synthesizing DNA. Incubation with Ara-C, in vitro, gave similar results, with 26.0% of Meg-CFC and 26.2% of GM-CFC in the spleen, and 27.1% of Meg-CFC and 31.4% of GM-CFC in the bone marrow, in cycle. In summary, significant differences were not observed between the cell cycle status of Meg-CFC and GM-CFC, whether derived from spleen or bone marrow. In vitro and in vivo measurements (with OHU) and in vitro measurements with two cytotoxic drugs (OHU versus Ara-C) also provided similar results. The data suggest that the regulation of DNA synthesis in both Meg-CFC and GM-CFC in the murine spleen and bone marrow is similar.
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Department of Laboratory Medicine, University of California School of Medicine, San Francisco.
Levin
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D000818:Animals; D001853:Bone Marrow / Q000378:metabolism; D001854:Bone Marrow Cells; D002453:Cell Cycle / Q000502:physiology; D002478:Cells, Cultured; D003561:Cytarabine / Q000494:pharmacology; D004247:DNA / Q000378:metabolism; D005260:Female; D006098:Granulocytes / Q000166:cytology* / Q000378:metabolism; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000378:metabolism; D006918:Hydroxyurea / Q000494:pharmacology; D008264:Macrophages / Q000166:cytology* / Q000378:metabolism; D008533:Megakaryocytes / Q000166:cytology* / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D013154:Spleen / Q000166:cytology* / Q000378:metabolism
D003561:Cytarabine; D004247:DNA; D006918:Hydroxyurea