THE REDISTRIBUTION OF GRANULOCYTES FOLLOWING E. COLI ENDOTOXIN-INDUCED SEPSIS

Infusion of endotoxin elicits granulocytopenia followed by increased n umbers of granulocytes in peripheral blood. The purpose of this study was to investigate the redistribution and sequestration of granulocyte s in the tissues following E. coli endotoxin induced sepsis. From 16 r abbits granulocytes were isolated, labelled with Indium and reinjected intravenously. Fight rabbits received an infusion of E. coli endotoxi n 2 mu g kg(-1) while eight received isotonic saline. The redistributi on of granulocytes was imaged with a gamma camera and calculated with a connected computer before and 2 and 6 hours after infusion of endoto xin or saline. Serum cortisol and interleukin-1 beta were measured. In another seven rabbits, respiratory burst activity and degranulation o f granulocytes were measured prior to and from 5 min to 6 hours after infusion of E. coli endotoxin 2 mu g kg(-1) BW. Following infusion of endotoxin, the number of granulocytes in peripheral blood decreased fr om 2.44 to 0.064 x 10 l(-1) two hours later. Within 5 min after infusi on the overall oxidative burst of the peripheral blood granulocytes wa s increased and the granularity had decreased. Serum cortisol and inte rleukin-1 beta increased significantly. The radioactivity of labelled cells in the bone marrow and spleen decreased to 83.1% and 91.6% of in itial values. At the same time there was a transient sequestration of labelled granulocytes in the lungs reaching 117.6% of initial values. The radioactivity of the liver increased continuously to 118.4%. The r esults indicate that endotoxin induces an efflux in activated granuloc ytes from peripheral blood, bone marrow and spleen to the lungs and li ver. The sequestration of granulocytes may contribute to the developme nt of ARDS and liver failure in sepsis.