Conclusion. Injection of endotoxin into the middle ear causes production of macrophage migration inhibitory factor (MIF) in an experimental mouse model of otitis media with effusion (OME). Down-regulation of MIF may become a new approach for the management of OME. Objective. To determine the role of MIF in OME. Materials and methods. Mice were divided into two groups and their middle ears were injected with either endotoxin or phosphate-buffered saline (PBS). Mice were sacrificed at 6 h, 12 h, or 1, 3, 7, or 14 days after injection and concentrations of MIF, interleukin-1 beta (IL-1β) and tumor necrosis factor-alpha (TNF-α) in middle ear effusions were measured by enzyme-linked immunosorbent assay. Results. Concentrations of MIF in the endotoxin group at 1 day and 3 days were significantly higher than in the PBS control group. Concentrations of IL-1β in the endotoxin group at 6 h, 12 h, 1 day, and 3 days were significantly higher than in controls. Concentrations of TNF-α in the endotoxin group at 1 day and 3 days were significantly higher than in controls. Concentration of MIF in the endotoxin group was positively correlated with that of IL-1β and TNF-α.
Bibliographical noteFunding Information:
The authors thank Bruce Lindgren for his statistical advice and Carolyn R. Sutherland for her technical support. This work was supported by NIDCD R01 DC006452, NIDCD P30 DC04660, International Hearing Foundation, Hubbard Foundation, Starkey Foundation, and Ministry of Education, Culture, Sports, Science and Technology, Japan.
- Middle ear
- Otitis media