Schematic presentation showing the possible route of IL-6, IL-8, and IL-13 signaling. Endogenous IL-1β production may occur with immune challenge by cytokines, bacteria, and viruses, and any microtrauma in the body while epinephrine is released in states of stress or sympathetic nervous system activation. The pathways activated by these signals converge on IL-6, IL-8, and IL-13 genes to induce cytokine production that is greater than either signal alone. IL-1β activates the NF-κB pathway which leads to significant amounts of IL-6, IL-8, and IL-13 production. Epinephrine activates the p38 MAPK pathway which may activate other transcription factors or stabilize the IL-6, 8, and 13 mRNA. From our data it is evident that IL-1β and epinephrine do not combine to further activate NF-κB or the promotor activity of the IL-13 gene. The importance of IL-6, IL-8, and IL-13 are listed in the figure.