title: The time course of DNA repair following methyl nitro-nitrosoguanidine (MNNG) treatment of P388F lymphoma cells in culture. I. Alkali dissociable DNA lesions and their restitution.
abstract: The pattern of formation and rejoining of P388F cell DNA single strand breaks revealed by alkaline sedimentation centrifugation studies following treatment with methyl nitro-nitrosoguanidine (MNNG) has been studied. Three periods of single strand break formation have been recognised, an initial period during the first 4 h where breaks are rapidly formed and rejoined, a second (medial) time range of 10-15 h following treatment and a final stage where the formation of breaks appears to be related to cell killing processes. The initial phase is considered to be due to the production and repair of X-ray like DNA lesions whereas those of the medial time range are more comparable to the enzymatic processes associated with the repair of ultraviolet light-induced damage.
mesh_terms: D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D002499:Centrifugation, Density Gradient; D004260:DNA Repair; D004277:DNA, Single-Stranded / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D008769:Methylnitronitrosoguanidine / Q000494:pharmacology*; D008970:Molecular Weight; D009604:Nitrosoguanidines / Q000494:pharmacology*; D013698:Templates, Genetic; D013997:Time Factors
chemical_list: D004277:DNA, Single-Stranded; D009604:Nitrosoguanidines; D008769:Methylnitronitrosoguanidine