title: [Relation of double-stranded DNA breaks and their repair to cell death and recovery after methylnitrosourea exposure].
abstract: The yield of DNA double-strand breaks (DSB) in the cells of mouse lymphosarcoma treated with nitrosomethylurea (NMU) was registered by means of elastoviscosimetry. It was shown that after short-term (7 min) treatment with NMU the lesions formed in DNA are efficiently repaired both in complete and conditioned media. After long-term (30 min) treatment DNA was only repaired in complete growth medium. The yield of the first fixed DSB after long-term NMU treatment correlated with the mean lethal dose D0. After short-term NMU treatment the first DSBs are registered in the dose range which is 4-fold higher than D0. The nature of lethal and potentially lethal lesions as well as the participation of various repair systems in the elimination of potentially lethal lesions are discussed.
mesh_terms: D000818:Animals; D002470:Cell Survival / Q000187:drug effects; D004247:DNA / Q000378:metabolism*; D004260:DNA Repair / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D007739:L Cells / Q000187:drug effects* / Q000378:metabolism; D008770:Methylnitrosourea / Q000494:pharmacology*; D051379:Mice; D009607:Nitrosourea Compounds / Q000494:pharmacology*; D013997:Time Factors
chemical_list: D009607:Nitrosourea Compounds; D008770:Methylnitrosourea; D004247:DNA
vernacular_title: Sviaz' dvukhnitel'nykh razryvov DNK i ikh reparatsii s gibel'iu i vosstanovleniem kletok posle vozdeĭstviia metilnitrozomocheviny.