Changes of activated macrophages and apoptotic cell count in the organs of rats during experimental sepsis

Leukocyte migration plays an important role in inflammation. The aim of our study was to detect the activated macrophage count and to define the apoptotic cell count in the rat's liver and lungs during different stages of sepsis and to clarify whether the activity of macrophages is associated with the apoptotic cell count in the course of the septic process.

Experimental sepsis was induced by inoculating Wistar rats intraperitoneally with E. coli cells. The liver and lung tissue was obtained 2, 6, 24, 48 and 120 hours after inoculation, and blood smears to detect the leukocyte volume were prepared at the same time. Macrophage activity was studied by immunohistochemical staining, using the ABC method. Apoptotic cell count was detected with the "In Situ Cell Death Detection Kit".

Decrease in the total count of leukocyte and lymphocyte percentage and a rise in the percentage of neutrophils in the blood were evidences of a strong inflammation process in an organism. The count of activated macrophages in the liver was high, showing the maximum level at the end of the 2(nd) h after inoculation, after which it began to fall. Apoptotic cell count rose after a decrease in macrophage activity. In the lungs both changes - a decrease in activated macrophage level and a rise in the apoptotic cell count took place later on.

Our investigations indicate that a decrease in the activated macrophage level is connected with an increased rise in the apoptotic cell count in both organs depending on the stage of the disease and occurs in the liver earlier than in the lungs but the process of cell apoptosis was more intensive in the lungs.