title: [Molecular mechanisms of radiation death of lymphoid cells. Radioprotective effect of cysteamine on a subpopulation of thymocytes differing in radiation sensitivity].
abstract: The radioprotective effect of cysteamine, incubated with thymocytes for 20 min prior to gamma-irradiation, was much more manifest with regard to subpopulations of radiosensitive small cortical cells (DMF = 1.8) than large thymocytes (DMF = 1.2). Radioprotective concentrations of cysteamine relaxed completely superhelical DNA of thymocytes. The relaxation was not due to the formation of single-strand breaks. A partial recovery of superhelical conformation of DNA of small thymocytes before irradiation reduced the radioprotective effect of cysteamine.
mesh_terms: D000818:Animals; D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects*; D003037:Cobalt Radioisotopes; D003543:Cysteamine / Q000494:pharmacology*; D004278:DNA, Superhelical / Q000528:radiation effects; D004305:Dose-Response Relationship, Drug; D004307:Dose-Response Relationship, Radiation; D005720:Gamma Rays; D008297:Male; D051379:Mice; D011836:Radiation Tolerance; D011837:Radiation-Protective Agents; D013950:Thymus Gland / Q000166:cytology* / Q000187:drug effects / Q000528:radiation effects
chemical_list: D003037:Cobalt Radioisotopes; D004278:DNA, Superhelical; D011837:Radiation-Protective Agents; D003543:Cysteamine
vernacular_title: Issledovanie molekuliarnykh mekhanizmov radiatsionnoĭ gibeli limfoidnykh kletok. Radiozashchitnoe deĭstvie tsisteamina na subpopuliatsii timotsitov, razlichaiushchiesia po radiochuvstvitel'nosti.