Effects of endotoxic shock in several functions of murine peritoneal macrophages

Gram negative sepsis and septic shock continue to be a major medical proble m, with a complex physiopathology and it is associated with high mortality. Although secretion of cytokines such as tumor necrosis factor-alpha by mac rophages is the principal host mediator of septic shock, other characterist ic functions of macrophages implicated in their phagocytic capacity have no t been studied in the process of endotoxic shock. In the present study we h ave used an intraperitoneal injection of E. coli lipopolysaccharide (LPS) ( 100 mg/kg) in order to obtain an endotoxic shock model in adult female BALB /c mice. Peritoneal cell suspensions were obtained at several times (2, 4, 12 or 24 h) after injection and the following functions were studied on the peritoneal macrophages: adherence to substrate, mobility (spontaneous and directed or chemotaxis), ingestion of particles and superoxide anion produc tion. The results showed a stimulation of adherence, ingestion and superoxi de production as well as a decrease of chemotaxis in the animals injected w ith LPS. These effects changed with time after LPS injection. Thus, the inc rease of adherence and the decrease of mobility were higher during the firs t hours, whereas the increase in ingestion and superoxide production turned larger with time.