BACKGROUND: The purpose of this study was to examine how RU486 (mifepristone), a glucocorticoid antagonist, affects the regeneration process in a rabbit laryngeal wound-healing model. MATERIAL/METHODS: Eight rabbits underwent a cricoid-split operation with collagen sponge insertion. The animals were classified randomly into two groups (4 animals in each group): the RU486-treated group, with local administration of 3 mg RU486, and the control group, which was sham treated. The specimens were harvested seven days after surgery. Histomorphometric analysis was performed to evaluate the healing pattern of the larynx wound. RESULTS: Respiratory epithelium regeneration was delayed in the RU486-treated group. The proliferation of granulation tissue was also increased. Polyps were detected in 3 specimens from this group. No obvious differences with regard to inflammatory cell infiltration were found. CONCLUSIONS: RU486 impairs post-surgical wound healing of the larynx by increasing the presence of granulation tissue and polyps, and appears to delay re-epithelialization.

Keywords: Larynx - drug effects, Larynx - metabolism, Larynx - pathology, Larynx - surgery