title: Sensitising effect of misonidazole on NHIK 1922 cells irradiated in vitro or as solid tumour in athymic nude mice.
abstract: The sensitising effect of the hypoxic cell sensitiser misonidazole (MIS) on NHIK 1922 cells irradiated either as single cells in vitro or as tumours in vivo in air-breathing and in dead mice was investigated with subsequent determination of in vitro colony-forming ability. In absence of MIS no significant difference was found between the dose-response curves after irradiation of tumours in dead mice and of cells in suspension under hypoxic conditions. After irradiation of tumours in air-breathing mice the same enhancement ratio of 1.4 was found whether MIS was administered in doses of 250 or 1000 micrograms/g body weight. In dead mice the enhancement ratio was 1.3 and 2.6 after 250 and 1000 micrograms/g, respectively. The sensitising effect of MIS for cells irradiated in suspension under extremely hypoxic conditions corresponded to that found in dead mice when a comparable concentration of MIS was used.
mesh_terms: D000818:Animals; D002460:Cell Line; D002470:Cell Survival / Q000528:radiation effects; D003114:Colony-Forming Units Assay; D004305:Dose-Response Relationship, Drug; D000860:Hypoxia; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D008920:Misonidazole / Q000494:pharmacology*; D009374:Neoplasms, Experimental / Q000532:radiotherapy*; D009593:Nitroimidazoles / Q000494:pharmacology*; D011837:Radiation-Protective Agents / Q000494:pharmacology*
chemical_list: D009593:Nitroimidazoles; D011837:Radiation-Protective Agents; D008920:Misonidazole