The mechanism by which bacterial endotoxin induces granulocytosis in man has been investigated by labeling granulocytes with radioactive diisopropylfluorophosphate. In man, a moderate dose of bacterial endotoxin produces a granulocytosis. By labeling circulating granulocytes with DF32P and later giving endotoxin intravenously, the rates of granulocyte inflow and egress from the blood were measured. Equations were written which express these flow rates as a function of the variables derived from the experimental data. These equations were solved for several time intervals during the 24-hr experiments in each of 12 normal subjects. In the six subjects in whom there was a significant granulocytic response to endotoxin there was a mean increase of 180% (58-383) in the rate of granulocyte inflow to the blood and 150% (24-420) in the rate of egress of granulocytes from the blood during the 5-hour period immediately after endotoxin injection. The remaining six subjects did not have a granulocyte response beyond the 99% limits of normal and there was random variation of inflow and egress of granulocytes. In vitro studies with DFP-labeled cells incubated with endotoxin failed to demonstrate a direct effect of endotoxin on the cell label.
|Number of pages||5|
|Journal||Proceedings of the Society for Experimental Biology and Medicine|
|State||Published - Jul 1971|