DETECTION OF DNA-ADDUCTS BY P-32 POSTLABELING FOLLOWING CHRONIC EXPOSURE OF RATS TO SNUFF

A surgically created canal was used as a reservoir for instillation of snuff into the lower lip of rats for 10 weeks. DNA was isolated and d igested with micrococcal nuclease/spleen phosphodiesterase. Polar DNA adducts were detected in all tissues examined when digests were fracti onated by high performance liquid chromatography (HPLC), P-32 postlabe led, 3' dephosphorylated and analyzed by two-dimensional thin layer ch romatography (TLC). DNA adducts derived from aromatic carcinogens were not detected when digests were P-32 postlabeled and analyzed by four- dimensional thin layer chromatography. These results suggest that non- aromatic agents initiate carcinogenesis following exposure to snuff. T he adduction to DNA in organs of the gastrointestinal tract and the ki dneys indicates that snuff usage results in systemic exposure to carci nogens and may contribute to the incidence of neoplasms in organs outs ide the oral cavity. (C) 1997 Elsevier Science Ireland Ltd.