Inflamatory Changes in Laryngeal Mucosa in Rats Due to Acid, Nitrite and Pepsin Exposition.

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, intraepithelial neoplasia or invasive carcinomas were seen. Inflammatory changes were observed in varying degrees. Discussion: Several authors demonstrated the cocarcinogenic 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.