Chi Zhang1, Kieran Paddock2, Adriana Chou2, Austin Scholp2, Ting Gong1, Jack J Jiang3,4. 1. Department of Otolaryngology-Head and Neck Surgery, Eye, Ear, Nose, and Throat Hospital of Fudan University, 83 Fenyang Road, Shanghai, 200031, China. 2. Division of Otolaryngology-Head and Neck Surgery, Department of Surgery, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, 53792, USA. 3. Department of Otolaryngology-Head and Neck Surgery, Eye, Ear, Nose, and Throat Hospital of Fudan University, 83 Fenyang Road, Shanghai, 200031, China. jjjiang@wisc.edu. 4. Division of Otolaryngology-Head and Neck Surgery, Department of Surgery, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, 53792, USA. jjjiang@wisc.edu.
Abstract
PURPOSE: Voice abuse is known to be a common risk factor of voice disorders and prolonged; high-intensity phonation has been shown to damage the vocal fold epithelium. We aim to evaluate the effects of phonation on the integrity and barrier function of vocal fold epithelium using a porcine laryngeal model. METHODS: Ex vivo porcine larynges were phonated at low intensity or high intensity for 15, 30, or 60 min within 4 h after harvest. Vocal fold epithelium was visualized using transmission electron microscopy (TEM). The barrier function of vocal fold epithelium was evaluated by measuring the permeability to model molecules, fluorescein (376 Da), and fluorescein isothiocyanate (FITC)-dextrans of 4000 and 10,000 Da (FD4, FD10), in a Franz diffusing cell. RESULTS: Cell death and dilated intercellular space after phonation were observed using TEM. Thickness of vocal fold epithelium was significantly reduced after low-intensity phonation for 30 and 60 min and high-intensity phonation for 15, 30, and 60 min. Epithelial permeability to fluorescein was significantly increased after low-intensity phonation for 30 and 60 min, and high-intensity phonation. Permeability to FD4 was significantly increased after high-intensity phonation for 30 and 60 min. Phonation did not alter the permeability to FD10 significantly. CONCLUSION: Long-duration phonation destroys the integrity and barrier function of vocal fold epithelium. These effects likely make vocal folds more vulnerable to other environmental irritants, such as tobacco smoke, reflux components, allergens, and inhaled pollutants. Destroyed barrier function may be an important factor in the pathogenesis of voice lesions related to voice abuse.
PURPOSE: Voice abuse is known to be a common risk factor of voice disorders and prolonged; high-intensity phonation has been shown to damage the vocal fold epithelium. We aim to evaluate the effects of phonation on the integrity and barrier function of vocal fold epithelium using a porcine laryngeal model. METHODS: Ex vivo porcine larynges were phonated at low intensity or high intensity for 15, 30, or 60 min within 4 h after harvest. Vocal fold epithelium was visualized using transmission electron microscopy (TEM). The barrier function of vocal fold epithelium was evaluated by measuring the permeability to model molecules, fluorescein (376 Da), and fluorescein isothiocyanate (FITC)-dextrans of 4000 and 10,000 Da (FD4, FD10), in a Franz diffusing cell. RESULTS: Cell death and dilated intercellular space after phonation were observed using TEM. Thickness of vocal fold epithelium was significantly reduced after low-intensity phonation for 30 and 60 min and high-intensity phonation for 15, 30, and 60 min. Epithelial permeability to fluorescein was significantly increased after low-intensity phonation for 30 and 60 min, and high-intensity phonation. Permeability to FD4 was significantly increased after high-intensity phonation for 30 and 60 min. Phonation did not alter the permeability to FD10 significantly. CONCLUSION: Long-duration phonation destroys the integrity and barrier function of vocal fold epithelium. These effects likely make vocal folds more vulnerable to other environmental irritants, such as tobacco smoke, reflux components, allergens, and inhaled pollutants. Destroyed barrier function may be an important factor in the pathogenesis of voice lesions related to voice abuse.
Authors: Tsuyoshi Kojima; Mark Van Deusen; W Gray Jerome; C Gaelyn Garrett; M Preeti Sivasankar; Carolyn K Novaleski; Bernard Rousseau Journal: PLoS One Date: 2014-03-13 Impact factor: 3.240