Redistribution of lymphocytes following E. coli sepsis

Infusion of endotoxin elicits lymphopenia and a transient granulocytopenia followed by granulocytosis in peripheral blood. The purpose of this study was to investigate which tissues the lymphocytes are redistributed to in response to endotoxaemia. Lymphocytes were isolated from the peripheral blood of 20 rabbits, labelled with 111Indium-tropolene and reinjected intravenously into the rabbits. Ten rabbits received an infusion of Escherichia coli endotoxin 2 micrograms/kg-1, while 10 rabbits received isotonic saline and served as a control group. The redistribution of lymphocytes was imaged with a gamma camera, and calculated with an interfaced computer before, and 2, 4 and 6 h after infusion of endotoxin or saline. Interleukin-1 beta and serum cortisol were measured. Following endotoxaemia the lymphocytes in peripheral blood decreased from 1.95 10(9)/l to 0.83 6 h later. Interleukin-1 beta and serum cortisol increased significantly. The radioactivity of labelled cells in the spleen and in the heart and lungs decreased to 83.3% and 87.8% of initial values respectively, 6 h after infusion of endotoxin. The radioactivity of the lymphatic tissue in and around the intestine increased to 128.8% of initial values. The results indicate that endotoxaemia induces redistribution of lymphocytes from peripheral blood and spleen to lymphatic tissue.