CHANGES IN LYMPHOCYTE SUBPOPULATIONS AND ADHESION ACTIVATION MOLECULES FOLLOWING ENDOTOXEMIA AND MAJOR SURGERY

Major surgery as well as endotoxin-induced sepsis is accompanied by ly mphocytopenia in peripheral blood. The purpose of this study was to in vestigate the redistribution of lymphocyte subpopulations and adhesion /activation molecules on lymphocytes. Twenty-four rats were included i n the investigation. Eight rats received an intraperitoneal injection of E. coli endotoxin (2 mg kg(-1)), eight rats had a sham operation pe rformed while eight rats received isotonic saline and served as a cont rol group. Blood samples were obtained by making an incision in the ta il before and 2 and 5 h after surgery or administration of endotoxin o r saline. After isolation of lymphocytes by gradient centrifugation, f lowcytometric immunophenotyping was performed using CD2, CD3, CD4, CD8 , CD11/CD18, CD20, CD44 and MHC II monoclonal antibodies. Endotoxemia and surgery were both accompanied by increased serum cortisol, lymphoc ytopenia, and a decrease in CD2, CD3 and CD4 lymphocytes. Only endotox emia was followed by a decrease in CD8, CD11/CD18 and CD44 lymphocytes in peripheral blood. Our results show that several of the changes in lymphocyte subpopulations following surgery and sepsis are associated with increased serum cortisol. Sepsis is, in addition, accompanied by an upregulation of adhesion receptors.