Effects of endotoxin on hematopoiesis in irradiated and nonirradiated W/W/sup v/ mice

The interaction between the genetically deficient hematopoietic stem cells of W/Wv mice and the stimulation produced by bacterial endotoxin in irradiated and nonirradiated mice was studied. Effects of 25 μg S. typhosa endotoxin injected 1 day before irradiation proved to be similar to effects in +/+ normal mice in several respects. After 300 rads survival was increased from 23% to 77%, recovery of hemoglobin concentration began on day 13 rather than day 17 and granulocyte concentrations were maintained at approximately 1500 per mm3 compared to a drop to $350 \text{per} {\rm mm}^{3}$ on day 17 in those given no endotoxin. Erythrocytic spleen colonies were negligible whether or not endotoxin was given. Endotoxin induced granulocytic colonies in significant numbers as early as 5 days after 300 rads, but their peak number (on day 7) was comparable to that seen 4 days after 700 rads in endotoxin treated +/+ mice. Spleen and femur cells of nonirradiated W/Wv mice given nine daily endotoxi...