The use of a hypoxic cell radiosensitizer AK-2123 gave no improvement in thermoradiotherapy combined with hydralazine.
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.
Kozin
S V
SV
Kansai Medical University, Osaka, Japan.
Hasegawa
T
T
Kozina
L V
LV
Imamura
M
M
Akagi
K
K
Tanaka
Y
Y
Kagiya
V T
VT
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*
D011838:Radiation-Sensitizing Agents; D014230:Triazoles; C072690:AK 2123; D006830:Hydralazine