Glutamine accelerates interleukin‐6 production by rat peritoneal macrophages in culture

The effect of glutamine on the production of interleukin-6 (IL-6) was studied in rat peritoneal macrophages in culture. A maximal production of IL-6 was measured at 4 h in lipopolysaccharide (LPS)-stimulated macrophages, and addition of glutamine (5 mM) anticipated this increase by 1 h without any increase in the IL-6 mRNA level. The effect of glutamine required the presence of LPS. Thus, glutamine accelerates IL-6 production from the pre-existing mRNA. The effect of glutamine was not mediated by cell swelling since culture of macrophages in hypoosmotic condition decreased the production of IL-6 in the culture medium with a corresponding decrease in the IL-6 mRNA level.