Effect of Mitomycin C on bFGF, TGF-β1, KGF-1 Expressions after Myringotomy: An Animal Study

The purpose of this study was to evaluate the effect of topical mitomycin C (MMC) on growth factor expression in tympanic membrane (TM) wound healing.

Forty (20 male and 20 female) adult Wistar albino rats that varied from 250 to 300 g in weight were divided into five groups. In the first group, no intervention was performed, and the intact TMs were excised after the rats were sacrificed. In the other groups, both ears of rats underwent an electrocautery myringotomy procedure; MMC was applied to the right ears and saline to the left ones. In all groups, on the 3(rd), 7(th), 14(th), and 30(th) days, macroscopic examinations of TM patency and the expressions of transforming growth factor-β1 (TGF-β1), basic fibroblast growth factor (bFGF), and keratinocyte growth factor-1 (KGF-1) in TM epithelia, fibroblasts, and macrophages were performed by immunohistochemical staining and compared among the groups.

Complete healing was significantly less in the MMC group with respect to the saline group on the 7(th) and 14(th) days (p<0.05). On immunohistochemical study, no significant differences in the expressions of bFGF or KGF-1 were observed among the groups with one exception; on the 3rd day, the expression of TGF-β1 in macrophages was more elevated in the MMC group than in the saline group (p=0.001).

Application of MMC to acute perforations of the TM delays closure and has significant effects on some growth factors for certain durations.