title: Effect of cigarette-smoke condensate and norharman on the induction of SCEs by direct and indirect mutagens in CHO cells.
abstract: Cigarette-smoke condensate and norharman were investigated either alone or in combination with a number of direct or indirect mutagens for the induction of sister-chromatid exchanges (SCEs) in Chinese hamster ovary (CHO) cells. Cigarette-smoke condensate and norharman induced SCEs in these cells, only in the presence of a metabolic activation system. The number of SCEs induced by the direct-acting mutagens mitomycin C and N-methyl-N'-nitro-N-nitrosoguanidine was decreased in the presence of cigarette-smoke condensate or norharman. However, cigarette-smoke condensate and norharman showed synergistic effects in combination with the indirect mutagens 2-acetylaminofluorene, 2-aminofluorene, N-hydroxy-acetylaminofluorene, 2-aminoanthracene and benzo[a]pyrene. No synergism was observed when CHO cells were treated simultaneously with cigarette-smoke condensate or norharman and the indirect mutagen cyclophosphamide.
mesh_terms: D000470:Alkaloids / Q000633:toxicity*; D000818:Animals; D002243:Carbolines; D002460:Cell Line; D006224:Cricetinae; D004357:Drug Synergism; D006247:Harmine / Q000031:analogs & derivatives / Q000633:toxicity*; D009152:Mutagenicity Tests; D009153:Mutagens; D010947:Plants, Toxic; D012854:Sister Chromatid Exchange / Q000187:drug effects*; D012906:Smoke; D014026:Nicotiana
chemical_list: D000470:Alkaloids; D002243:Carbolines; D009153:Mutagens; D012906:Smoke; D006247:Harmine; C010262:norharman