title: The use of a hypoxic cell radiosensitizer AK-2123 gave no improvement in thermoradiotherapy combined with hydralazine.
abstract: An electron-affinic compound, AK-2123, and the anti-hypertensive agent, hydralazine, were combined with radiation and hyperthermia for treatment of murine SCC-VII tumours. Hydralazine markedly decreased tumour perfusion while AK-2123 had no influence on it. Hydralazine enhanced the tumouricidal effects of hyperthermia alone and in combination with radiation. AK-2123 provided a radiosensitization which was significant only in tumours irradiated without supplementary hyperthermia. The greatest tumour response was achieved when thermoradiotherapy was combined with hydralazine alone; the additional use of AK-2123 with this treatment combination did not further increase the effect. It is concluded that hydralazine plus heat virtually eliminated a hypoxia-related radioresistance in tumours, thus removing the requirement for AK-2123 administration.
authors.affiliation: Kansai Medical University, Osaka, Japan.
authors.forename: S V
authors.initials: SV
authors.lastname: Kozin
authors.forename: T
authors.initials: T
authors.lastname: Hasegawa
authors.forename: L V
authors.initials: LV
authors.lastname: Kozina
authors.forename: M
authors.initials: M
authors.lastname: Imamura
authors.forename: K
authors.initials: K
authors.lastname: Akagi
authors.forename: Y
authors.initials: Y
authors.lastname: Tanaka
authors.forename: V T
authors.initials: VT
authors.lastname: Kagiya
mesh_terms: D000818:Animals; D002294:Carcinoma, Squamous Cell / Q000628:therapy*; D003131:Combined Modality Therapy; D006830:Hydralazine / Q000627:therapeutic use*; D006979:Hyperthermia, Induced; D051379:Mice; D009374:Neoplasms, Experimental / Q000628:therapy*; D011838:Radiation-Sensitizing Agents / Q000627:therapeutic use*; D011878:Radiotherapy; D014230:Triazoles / Q000627:therapeutic use*
chemical_list: D011838:Radiation-Sensitizing Agents; D014230:Triazoles; C072690:AK 2123; D006830:Hydralazine