SUBGLOTTIC INJURY, GASTRIC-JUICE, CORTICOSTEROIDS, AND PEPTIDE GROWTH-FACTORS IN A PORCINE MODEL

Objectives: To study the effects of mucosal injury, gastric juice, and corticosteroids and to determine the presence of peptide growth facto rs in the subglottic mucosa in a porcine model. Study Design: Prospect ive cohort animal study. Methods: in this model of subglottic injury, five groups (n = 5 each) of piglets were used. injury was induced by e lectrocautery (acute), electrocautery plus repeated saline application (chronic), electrocautery plus repeated gastric juice application (ch ronic plus gastric juice), or repeated gastric juice application (gast ric). Control piglets had normal saline applied repeatedly, Results: H istopathologic findings for the gastric juice group included basal cel l hyperplasia (80%), squamous metaplasia (80%), and mucosal ulceration (40%). Control piglets showed squamous metaplasia (80%) but mo basila r hyperplasia or ulceration. Immunohistochemistry detected peptide gro wth factors and epidermal growth factor receptor (EGFR) in all groups, Decreased staining was most frequent ha the acute injury group. Quant itative reverse transcriptase polymerase chain reaction (RT-PCR) docum ented lower expression of EGFR in the gastric juice group (P =.01). Co nclusions: These findings suggest that peptide growth factors and EGFR are part of normal subglottic mucosal turnover, Noxious stimuli decre ase production of these factors. Gastric juice had adverse effects doc umented by histopathology and molecular techniques.