RESUMO
To investigate the extent to which intratracheal intubation may alter the respiratory epithelium of the Syrian golden hamsters, single and repeated intubations were undertaken and the resulting injury and subsequent epithelial regeneration were examined by scanning electron microscopy. Generally, epithelial injury as a result of a single intubation had healed ad integrum within 20 to 40 days. On the other hand, repeated treatment often caused tracheitis and led to prolonged regeneration which sometimes persisted as papillary hyperplasia 40 days after the final intubation. The appropriateness of intratracheal instillation as a method of administering chemical carcinogens and the similarity of the epithelial regeneration processes to early neoplastic alterations of the epithelium are discussed.
