A Dichotomy between the Release of Bone Marrow Granulocytes and Stem Cells

Abstract
Control CF1 mice injected ip with 5 μg of S. typhosa endotoxin release marrow granulocytes and granulocyte-mac-rophage in vitro colony-forming cells (CFC). Mice repetitively injected with 10 μg of endotoxin daily for 7 days and then challenged on Day 8 with 5 μg of endotoxin release granulocytes but not CFC from the marrow, indicating that the mechanisms governing release are dissimilar for the two cell types.