Combined effects of misonidazole radiosensitization and hypoxic cell toxicity in mammalian cells
It has been established that the hypoxic cell radiosensitizer misonidazole (Ro-07-0582) is also a toxic agent to hyposic cells in the absence of radiation. In this study, the combined effects of radiation sensitization and toxicity were examined in hypoxic CHO cells. Complete radiation survival curves were measured for cells in the presence of 15 mM misonidazole prior to or following incubation with the drug for various times in hypoxia at 37/sup 0/C. The latter case is the condition for the preincubation effect observed previously for misonidazole. The cells were irradiated as a monolayer in stoppered glass flasks with 280-kVp x rays; survival was assayed by colony formation. The survival data obtained in these experiments were analyzed by comparing the experimentally observed survival curves with those theoretically predicted based on the concepts of independent and additive interaction of the two effects of hypoxic cell toxicity and radiation sensitization. For incubation times of 1 to 3 hr, for which the cytotoxic effect is moderate, the combined response appears to be of an additive rather than an independent nature. The data in fact suggest a somewhat greater than additive response, and also a slight change in the slope as well as the shoulder of the survival curve, when compared with the predicted curves. The results are discussed with regard to both in vitro and in vivo studies.
- OSTI ID:
- 5821086
- Journal Information:
- Radiat. Res.; (United States), Journal Name: Radiat. Res.; (United States) Vol. 88:2; ISSN RAREA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMAL CELLS
AZOLES
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
BIOLOGY
CYTOLOGY
DRUGS
ELECTROMAGNETIC RADIATION
HETEROCYCLIC COMPOUNDS
IMIDAZOLES
IONIZING RADIATIONS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
RADIATION EFFECTS
RADIATIONS
RADIOSENSITIVITY
RADIOSENSITIVITY EFFECTS
RADIOSENSITIZERS
TOXICITY
X RADIATION