Hemopoiesis in Diffusion Chambers in Strontium-89 Marrow-Ablated Mice 1

Summary

The numbers of pluripotent stem cells (CFU-S) and of the more differentiated granulocyte/macrophage elements in diffusion chambers (DCs) implanted into the peritoneal cavities of radio-⁸⁹Sr-marrow-ablated mice are increased as compared to those in DCs implanted into cold-⁸⁸ Sr-mar-row-ablated mice. These findings suggest that there is a systemic humoral response capable of stimulating hemopoiesis even in mice with aplastic marrows and whose hemopoiesis is localized to their spleens. The magnitude of this response and the promptness with which the response is manifest in DC growth suggests that marrow aplasia induced by ⁸⁹Sr provides a stronger stimulus for proliferation of cells in DCs than does either cyclophosphamide or lethal external whole-body irradiation.