Histological and immunohistochemical changes in the rat oral mucosa used as an autologous urethral graft

PurposeThe purpose of this study was to determine the histological and functional (immunohistochemical) changes that take place in oral mucosa grafts implanted in the rat urethra.MethodsUrethroplasty was performed in 26 male Wistar rats weighing 250 g. All animals received autologous oral mucosa urethra grafting under general anesthesia. Samples were analyzed 10, 20, 30, 40, 50, 60, 90, and 120 days after surgery using light and scanning electron microscopy and immunofluorescence for the determination of the expression of epithelial markers (pancytokeratin, cytokeratin 1, 4, 13, and filaggrin).ResultsGrafted oral mucosa tissues were subjected to significant histological changes from the beginning with the formation of a well-developed epithelium whose structure was comparable to the native urethra from day 60 of the surgical implant. The immunofluorescence analysis demonstrated that the cytokeratin expression profile tended to mimic the pattern of the native urethra. These data suggest that the oral mucosa is able to efficiently transdifferentiate to the urethral environment.ConclusionsThe efficient transdifferentiation process of the grafted oral mucosa at both the histological and immunofluorescence levels, and the absence of local complications confirm the clinical usefulness of this type of tissues for the repair of the urethra.