Production of tumor necrosis factor, interleukin-6 and prostaglandin E2 by LPS-stimulated rat bone marrow macrophages after thermal injury: effect of indomethacin.

The effect of thermal injury on the in vitro production of TNF, IL-6, and PGE2 by bone marrow-derived, LPS-stimulated rat macrophages was studied. Thermal injury caused a general hyperactivity in the production of the mediators by the cells. Indomethacin, a cyclooxygenase inhibitor of PGE2 synthesis, inhibited the production of IL-6 and PGE2 but had no effect on the production of TNF. These results suggest that the observed low concentration of PGE2 produced by the cells was insufficient to cause inhibition of TNF synthesis; thus, the effect of indomethacin would be undetectable. The results also suggest that indomethacin may act directly in inhibiting the production of IL-6 by the macrophages. The hyperactive effect of thermal injury on the production of inflammatory mediators by newly differentiated bone marrow derived macrophages can be important in the overall systemic response to the insult.