The assessment of DNA damage and repair in rat nasal epithelial cells.
A methodology for the isolation and culture of rat nasal turbinates was developed with the aim of studying chemically-induced genotoxic effects in the nasal epithelium. DNA damage, as assessed by alkaline elution, and unscheduled DNA synthesis, as measured by quantitative autoradiography, were observed in the cells of the respiratory and olfactory epithelium as a result of in vitro treatment with methyl methanesulfonate. The capacity of nasal epithelium to metabolize the promutagen dimethylnitrosamine (DMN) was demonstrated by the induction of both DNA strand breakage and the induction of unscheduled DNA synthesis. Although a response was observed in all of the epithelia examined, differences in response to DMN were observed that were not attributable to the differences in the cell types present (e.g., respiratory versus olfactory epithelium). The respiratory epithelial cells of the maxilloturbinate were found to be resistant to the induction of DNA damage at concentrations of 0.5 and 1.0 mM DMN, whereas the respiratory epithelial cells of the nasoturbinates were susceptible. In contrast, the response of the olfactory epithelium was similar to the response observed in the cells of the nasoturbinates. These techniques should prove valuable in assessing chemically-induced DNA damage and repair in this target tissue.
D000818:Animals; D004247:DNA / Q000032:analysis / Q000096:biosynthesis; D004260:DNA Repair / Q000187:drug effects*; D004128:Dimethylnitrosamine / Q000633:toxicity; D004848:Epithelium / Q000187:drug effects; D066298:In Vitro Techniques; D008297:Male; D008741:Methyl Methanesulfonate / Q000633:toxicity; D009666:Nose / Q000187:drug effects*; D051381:Rats; D011916:Rats, Inbred F344; D014420:Turbinates / Q000187:drug effects
D004247:DNA; D008741:Methyl Methanesulfonate; D004128:Dimethylnitrosamine