title: Cytotoxicity, chromosome aberrations and unscheduled DNA synthesis in cultured human diploid fibroblasts induced by sodium fluoride.
abstract: The effects of exposure of cultured human diploid fibroblasts (JHU-1 cells) to sodium fluoride have been studied with respect to cytotoxicity and induction of chromosome aberrations and unscheduled DNA synthesis (UDS) Cytotoxicity of NaF on JHU-1 cells, as determined by a decrease in colony-forming ability, linearly increased with increasing dose of NaF (50-150 micrograms/ml) or exposure time (1-24 h). Treatment of the cells with 50 micrograms/ml NaF for 24 h resulted in a lethality (approximately 70%) similar to that obtained with 100 micrograms/ml for 12 h. A linear increase in cytotoxicity was observed as a fraction of the product of NaF treatment time and dose. JHU-1 cells treated with 20-50 micrograms/ml NaF for 12 or 24 h were analyzed for chromosome aberrations. A significant increase in the frequency of chromosome aberrations at the chromatid level was observed in treated cells in a dose-dependent manner. For detection of UDS, confluent JHU-1 cells were cultured with medium containing low serum and then exposed to NaF in the presence of 10 mM hydroxyurea. Treatment with 100-400 micrograms NaF/ml for 4-24 h reproducibly elicited UDS in a dose-related fashion as determined by direct scintillation counting of [3H]thymidine incorporated into DNA during repair synthesis. These results suggest that NaF causes DNA damage in human diploid fibroblasts in culture.
mesh_terms: D002470:Cell Survival / Q000187:drug effects*; D002478:Cells, Cultured; D002869:Chromosome Aberrations; D004247:DNA / Q000096:biosynthesis; D004260:DNA Repair / Q000187:drug effects*; D006801:Humans; D006918:Hydroxyurea / Q000494:pharmacology; D009154:Mutation / Q000187:drug effects*; D012969:Sodium Fluoride / Q000633:toxicity*
chemical_list: D012969:Sodium Fluoride; D004247:DNA; D006918:Hydroxyurea