title: Cells forming spleen colonies at 7 or 11 days after injection have different proliferation rates.
abstract: In the early periods (7-9 days) after haemopoietic cell injection, colonies produced by CFU-s and by their progeny are identified in the spleen, while at later periods (11 days after injection) only spleen nodules produced by CFU-s persist. The increase in the suicide values of CFU-s after sublethal (2 Gy) irradiation of mice is associated with a higher proliferation rate of precursors of transitory spleen colonies, but not of CFU-s, as measured by different suicide techniques. During the log-phase of cell growth in a lethally irradiated recipient, the injected CFU-s and CFU-tr proliferate at a higher rate. Active proliferation of CFU-s and CFU-tr has been demonstrated in long-term bone-marrow cultures by the hydroxyurea in-vitro suicide assay. CFU-tr may be the cause of artifactual effects during measurement of haemopoietic stem-cell cycling by CFU-s suicide methods.
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells; D002455:Cell Division; D002470:Cell Survival; D002478:Cells, Cultured; D005260:Female; D006412:Hematopoietic Stem Cells / Q000502:physiology*; D051379:Mice; D008815:Mice, Inbred Strains; D013154:Spleen / Q000166:cytology*; D013997:Time Factors