title: [Patterns in the x-ray induction of mutations in resistance to 5-thioguanine in Chinese hamster cell cultures studied using cysteamine].
abstract: X-ray induction of 5-thioguanine resistance mutations and the protective effect of cysteamine were studied in cultured cells of chinese hamster clone 431. Expression of mutations was studied for 8--10 days of post-irradiated growth, when cells surviving radiation at doses 200, 400, 600, 800 R were passing from 3 to 12 generations. The maximum frequency of induced mutations was found after 3-5 generations. After reaching the maximum, the number of registered mutations decreased with the number of cell generations. Pre-irradiated treatment with 5mM cysteamine decreased induction of mutations 2--4 times when using doses 200--800 R. The frequency of mutations induced by mere radiation increased non-linearly with increasing doses, while in the presence of cysteamine the linear dose dependence was observed.
mesh_terms: D000818:Animals; D002478:Cells, Cultured / Q000528:radiation effects*; D006224:Cricetinae; D003412:Cricetulus; D003543:Cysteamine / Q000494:pharmacology*; D004307:Dose-Response Relationship, Radiation; D004351:Drug Resistance / Q000528:radiation effects; D009154:Mutation; D013866:Thioguanine / Q000037:antagonists & inhibitors*; D013997:Time Factors
chemical_list: D003543:Cysteamine; D013866:Thioguanine
vernacular_title: Izuchenie zakonomernosteĭ induktsii rentgenovymi luchami mutatsiĭ rezistentnosti k 6-tioguaninu v kul'turakh kletok kitaiskogo khomiachka v usloviiakh primeneniia tsisteamina.