Abstract
Injury caused by cuff pressure and regeneration in rat tracheal mucosa were examined immunohistochemically using BrdU and electron microscopy. Epithelial defects were observed in almost the whole circumference of the tracheal wall, while the partial existence of the epithelium was recognized in the membranous wall of the trachea. The submucosal layer showed severe edema, bleeding and thrombi. The BrdU labeling indices (L. I.) of the epithelial and submucosal layers started to increase at 12 and 24 hours after treatment, respectively, and reached their peak values in a similar manner at 36 hours. They then drastically decreased until the third and fifth days, respectively, after treatment. The changes in the mitotic indices showed a 12-hour delay compared with those in L. I. Migrating epithelial cells were observed in the area of the regenerating epithelial cells, composed of basal cell-like cells, from 6 to 48 hours after intubation.
