Histological changes of rat soft palate with exposure to experimental laryngopharyngeal reflux

Abstract

Objective: The possible effects of laryngopharyngeal reflux (LPR) on laryngeal and otologic disorders have been studied in the literature. There have been no reports explaining the possible effects of LPR on the soft palate. Therefore, in this study, we investigated the histopathologic changes in the rat soft palate using an experimental model of reflux. Subjects and methods: Eighteen healthy 200-220-g 20-week-old Sprague-Dawley rats were used. The animals were divided into three groups according to exposure time (1, 4, and 12 week exposures), and four rats were examined as controls who had undergone sham operation. An experimental model of gastroesophageal reflux was induced under general anesthesia. After exposure, the animals were sacrificed, and their soft palates were removed. The histopathological changes in the soft palates were observed under a light microscope. Results: Submucous gland hyperplasia, inflamation, subepithelial edema, vascular engorgement, muscular atrophy and dilated glandular excretory duct were compared among the groups. Submucous gland hyperplasia, subepithelial edema, inflammation, vascular engorgement, muscular atrophy and dilated glandular excretory duct were significantly different in the exposure groups compared with the control group. Conclusion: On the basis of histopathological evaluations, our findings suggest that reflux affects the soft palate, which suggests that these pathological changes may reflect the relationship between LPR and airway obstruction. (C) 2010 Elsevier Ireland Ltd. All rights reserved.