THE ROLE OF THE SPLEEN IN HEMATOPOIETIC-CELL PRODUCTION DURING THE ACUTE-PHASE OF STERILE INFLAMMATION IN RATS

The participation of splenic hematopoietic cells in the acute phase of sterile inflammation was investigated using rats with polyvinylpyrrol idone (PVP) - induced sterile inflammation as a model in vivo. Changes within splenic granulocytic-monocytic (CFU-GM) and erytrroid (BFU-E a nd CFU-E) committed stem cells determined in vitro in cell cultures, a s well as morphologically recognizable hematopoietic cells identified on May-Grunwald Giemsa smears and in histological sections, were estim ated at different time intervals during the first 24 hours of the acut e phase of inflammation. The data obtained demonstrated intensive prod uction of cells belonging to different granulocytic cell compartments during the observed periods. Also, an increased production of monocyte s was found although to much a smaller extent in comparison to granulo cytic cells. Although no changes within peripheral blood erythrocytes were found changes within different compartments of the erythroid cell lineage in the spleen indicated an increased production of erythroid cells during the acute inflammatory response. From the data presented it is obvious that different splenic hemopoietic cell lineages are act ivated during the acute phase of the inflammatory response implying si gnificant participation of extramedullary hemopoiesis in the whole bod y host defense reaction.