title: Synergistic action of cysteamine and BrdU-substituted DNA in the induction of sister chromatid exchanges.
abstract: The effect of different BrdU-concentrations on the cysteamine-induced SCE-rate was investigated in V-79 Chinese hamster cell monolayer cultures. Both cysteamine and its auto-oxidation product cystamine act synergistically with BrdU in the induction of SCEs. A given concentration of these substances produces a low SCE-frequency at low BrdU-concentrations -- but the incidence of SCEs is significantly increased at increased BrdU-concentrations. -- Using one-cycle substitution experiments and the determination of the relative level of substitution by means of 3HBrdU-incorporation, this synergism was shown to depend on the BrdU incorporated in the DNA and on the extent to which this incorporation takes place.
mesh_terms: D000818:Animals; D001973:Bromodeoxyuridine / Q000494:pharmacology*; D002460:Cell Line; D002842:Chromatids / Q000187:drug effects*; D006224:Cricetinae; D003412:Cricetulus; D003434:Crossing Over, Genetic; D003543:Cysteamine / Q000494:pharmacology*; D004247:DNA / Q000235:genetics*; D004305:Dose-Response Relationship, Drug; D008168:Lung; D012854:Sister Chromatid Exchange
chemical_list: D003543:Cysteamine; D004247:DNA; D001973:Bromodeoxyuridine