Cellular differentiation after free grafting of respiratory epithelia.

Since there have been few investigations on the free grafting of respiratory epithelia, the aim of our present experiments was to establish whether it was possible to carry out such grafting in an animal model. Purebred strains of Lewis blood group rats were used to avoid host-versus-graft rejections of mucous membrane transferred from a donor to a recipient animal. Respiratory epithelia from the nasal septum were transplanted to the rectus abdominis muscle. Muscle and epithelial layers were then removed 4 months later. Using light and electron microscopy the function of the grafted ciliated epithelia--i.e. of the ciliated and goblet cells--could be demonstrated. These findings showed that respiratory epithelia heal when grafted onto a recipient site which has an adequate blood supply but do not lose their initial differentiation or functions. The results obtained in this experiment are important clinically for reconstruction of the respiratory tracts.