Studies on the Regulation of Diffusion Chamber Granulopoiesis

Abstract

We have evaluated the role of colony-stimulating activity (CSA) and stem cells in diffusion chamber (DC) myelopoiesis. CF1 host mice were implanted with DC with 0.5 x 106 normal marrow cells and then injected for 3–4 days intravenously with 5 μg Salmonella typhosa endotoxin or saline. There were no significant increases in DC myelopoiesis, but significant increases in host animal total tibial proliferative granulocytes on day 4 and suggestive increases in nonproliferative granulocytes on day 7 of DC culture. Further studies utilizing progressively increasing doses of intravenous endotoxin in irradiated or normal host mice implanted with DC with normal marrow showed: (1) a lack of correlation of serum CSA or inhibitor level with DC myelopoiesis; (2) elevations of CSA levels within DC relative to serum levels in all groups; and (3) a general inverse correlation of DC myelopoiesis with marrow cellularity.