Inflamatory Changes in Laryngeal Mucosa in Rats Due to Acid, Nitrite and Pepsin Exposition
André Del Negro *
The R Egberto Ferreira Camargo 1200 ap64A, State University of Campinas, Brazil.
*Author to whom correspondence should be addressed.
Abstract
Smoking and alcoholism are risk factors for head and neck malignancies. Other possible risk factors for squamous cell carcinomas (SCC) are gastroesophageal (GER) and pharyngolaryngeal (PLR) refluxes. Objectives: Demonstrate the carcinogenic action of hydrochloric acid on the laryngeal mucosa of Wistar rats, potentialized by pepsin, associated with nitrate applied in the rat laryngeal mucosa, simulating the reflux of the gastric contents to the laryngopharynx. Method: Eighty-two Wistar rats were divided in seven groups and submitted to 2 or 3 weekly applications of hydrochloric acid, pepsin and sodium nitrate to the laryngeal mucosa during 6 months. Results: No dysplasia, intra-epithelial neoplasia or invasive carcinomas were seen. Inflammatory changes were observed in varying degrees. Discussion: Several authors demonstrated the co-carcinogenic action of GERD, whose mucosal irritating agent is hydrochloric acid. Conclusion: It is possible that GERD and PLR are co-carcinogenic due to the inflammatory action of hydrochloric acid potentialized by pepsin.
Keywords: Head and neck cancer, squamous cell carcinoma, gastroesophageal reflux, larynx, hydrochloric acid.