title: Effect of sodium selenite and methyl methanesulfonate or N-hydroxy-2-acetylaminofluorene co-exposure on sister-chromatid exchange production in human whole blood cultures.
abstract: Sodium selenite (Na2SeO3) was tested for its sister-chromatid exchange (SCE)-inducing ability in human whole blood cultures and for the effect of its co-exposure with methyl methanesulfonate (MMS)  or N-hydroxy-2-acetylaminofluorene (N-OH-AAF) on SCE frequency. Long exposure times (77 h and 96 h) to 3.95 X 10(-6) M Na2SeO3 resulted in cell death as measured by mitotic indices, but mitotic figures were present after exposure to higher concentrations for a shorter time (19 h). High Na2SeO3 concentrations (7.90 X 10(-6) and 1.19 X 10(-5) M) resulted in a three-fold increase in the SCE frequency above background level (6--7 SCEs/cell). Exposure of lymphocytes to 1 X 10(-4) M MMS for the last 19 h of culture yielded an average SCE frequency of 30.17 +/- 0.75 while a similar exposure to 2.7 X 10(-5) M N-OH-AAF resulted in 13.61 +/- 0.43 SCEs/cell. Simultaneous addition of the high Na2SeO3 concentrations and MMS or N-OH-AAF to the cultures resulted in SCE frequencies that were 25--30% and 11--17%, respectively, below the sum of the SCE frequencies produced by the individual compounds.
mesh_terms: D002470:Cell Survival; D002478:Cells, Cultured; D002875:Chromosomes / Q000187:drug effects*; D003434:Crossing Over, Genetic / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D005449:Fluorenes / Q000494:pharmacology*; D006801:Humans; D006881:Hydroxyacetylaminofluorene / Q000494:pharmacology*; D008214:Lymphocytes / Q000648:ultrastructure; D008297:Male; D008698:Mesylates / Q000494:pharmacology*; D008741:Methyl Methanesulfonate / Q000494:pharmacology*; D012643:Selenium / Q000494:pharmacology*; D013997:Time Factors
chemical_list: D005449:Fluorenes; D008698:Mesylates; D006881:Hydroxyacetylaminofluorene; D008741:Methyl Methanesulfonate; D012643:Selenium