title: Hemopoietic stem cell dynamics in 89Sr marrow-ablated mice.
abstract: 89Sr was used to ablate the marrows of 12- to 16-week-old CAF1 mice. The CFU-S of their blood, marrows, and spleens were assayed at intervals from days 10 through 56. The effects of splenectomy performed on day 14 or 42 on the numbers of CFU-S in the blood and marrow were also studied. On day 10 after treatment with 89Sr both the cellularity and CFU-S of the marrow were markedly decreased. Later, especially during the third week after treatment, marrow cellularity increased and by day 56 had returned to 74 percent of normal; the concentration of marrow CFU-S also increased but by day 56 had attained a level of only one-third normal. Thus, replenishment of the marrow's CFU-S lagged behind the repletion of its cellularity. Spleen and blood CFU-S were elevated throughout the 56 days. The number of splenic CFU-S was highest at day 10, decreased somewhat by day 21, and remained remarkably stable thereafter. After splenectomy there was a significant decline in the content of both blood and marrow CFU-S, whereas the reverse occurred in the "cold" 88Sr-treated control group. The results of these studies suggest that in the 89Sr-irradiated animal the spleen is transformed from a trapper to the prime supplier of CFU-S and that in normal mice the spleen may suppress marrow CFU-S proliferation. An inverse relationship between the size of the pool of mature granulocytes and the number of CFU-S was found, suggesting that the granulocyte compartment may, at least in part, play a role in the regulation of CFU-S proliferation.
mesh_terms: D000380:Agranulocytosis; D000818:Animals; D001853:Bone Marrow / Q000032:analysis / Q000528:radiation effects*; D002465:Cell Movement; D005260:Female; D006410:Hematopoiesis; D006412:Hematopoietic Stem Cells / Q000032:analysis / Q000502:physiology / Q000528:radiation effects*; D051379:Mice; D008815:Mice, Inbred Strains; D013154:Spleen / Q000032:analysis; D013156:Splenectomy; D013326:Strontium Radioisotopes
chemical_list: D013326:Strontium Radioisotopes