Time modulation effect of diethyldithiocarbamate (DDC) on radiosensitization by superoxide dismutase (SOD) inhibition.
Superoxide dismutase (SOD) is known to protect cells from the lethal effects of ionizing radiation by the dismutation of oxygen radicals. Diethyldithiocarbamate (DDC) is known inhibitor of SOD and may therefore be useful as a radiosensitizer. DDC however, is also a thiol radioprotector due to its ability to scavenge radiation induced free radicals. We have shown that DDC, if administered to tumours 1 hour prior to x-irradiation exerts a protective effect, whereas if administered 4 hours prior to irradiation, it radiosensitizes. This time modulation effect is not apparent after neutron irradiation where DDC protects in both situations. We have also examined the effect of DDC on the LD50/30 in mice after total body irradiation.
Kent
C
C
Research Institute for Medical Biophysics, Medical Research Council, Tygerberg, South Africa.
Blekkenhorst
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G
D000818:Animals; D004050:Ditiocarb / Q000494:pharmacology*; D007928:Lethal Dose 50; D051379:Mice; D008810:Mice, Inbred C57BL; D009368:Neoplasm Transplantation; D009502:Neutrons; D011837:Radiation-Protective Agents; D011838:Radiation-Sensitizing Agents; D012208:Rhabdomyosarcoma / Q000532:radiotherapy; D013482:Superoxide Dismutase / Q000037:antagonists & inhibitors*; D013997:Time Factors; D014916:Whole-Body Irradiation
D011837:Radiation-Protective Agents; D011838:Radiation-Sensitizing Agents; D004050:Ditiocarb; D013482:Superoxide Dismutase