title: The combined action of X-irradiation, drug and hyperthermia on the DNA in mammalian cells in vitro.
abstract: The effects of the alkylating cytostatic drug PTC on the production of radiation-induced single-strand breaks in DNA, and on the repair in L cells incubated at 37 degrees or 42 degrees C were studied. The same amount of SSB is obtained when the cells are treated simultaneously with PTC and hyperthermia as when irradiated with 2 500 rad, but different rate in the rejoining was observed. There is no potentiation of SSB formation by pretreatment of cells with 10 microgram PTC/ml for 2 hours at 42 degrees C before irradiation, but in these cells less effective repair occurs. The effect of PTC on the rejoining of SSB induced with 2 500 rad depends on the drug's concentration and post-incubation time.
mesh_terms: D000477:Alkylating Agents / Q000494:pharmacology; D000818:Animals; D004247:DNA / Q000528:radiation effects; D004260:DNA Repair; D005334:Fever; D006801:Humans; D066298:In Vitro Techniques; D007739:L Cells; D008558:Melphalan / Q000031:analogs & derivatives*; D010440:Peptichemio / Q000494:pharmacology*; D011829:Radiation Dosage; D013997:Time Factors
chemical_list: D000477:Alkylating Agents; D004247:DNA; D010440:Peptichemio; D008558:Melphalan