Oral focal acantholytic dyskeratosis induced in sialoadenectomized rats painted orally with the carcinogen 4-nitroquinoline N-oxide.

This study examines the effects of xerostomia on the development of mucosal changes proceeding carcinoma in rats painted orally with 4-nitroquinoline N-oxide (4NQO). Sialoadenectomy enhanced the incidence of focal acantholytic dyskeratosis (FAD) on the palate and tongue of rats painted on the palate with 0.5% 4NQO three times weekly. At one month, no changes were observed. After two months of painting with 4NQO, sialoadenectomized rats, but not controls, had FAD. After three months, FAD was seen in both test and control groups, but the incidence of FAD was higher in the test group and seen more on the palate than on the tongue of xerostomic animals. Neither test nor control animals developed carcinoma within this study period.