Effect of recombinant human interleukin-6 on nitrite production of mouse myeloid leukemia cells.

The effect of recombinant human interleukin-6 (rhIL-6) on induction of nitrite (NO(-2)) production was investigated in a mouse myeloid leukemia cell line (M1) and a subclone (Mm1). NO(-2) was induced by rhIL-6 (greater than 50 U/ml) in these cell lines. Pretreatment with rhIL-6 (100 U/ml) for 1 day synergistically enhanced the production of NO(-2) in Mm1 by LPS. Furthermore, pretreatment with IL-6 (100 U/ml) shortened the lag time of induction. These results indicate that IL-6 is involved in the regulation of the NO(-2) production in macrophage-like cells.