Combined radiation-protective and radiation-sensitizing agents. II. Radiosensitivity of hypoxic or aerobic Chinese hamster fibroblasts in the presence of cysteamine and misonidazole: implications for the oxygen effect (with Appendix on calculation of dose-modifying factors. [/sup 60/Co]

Journal Article · Sat Aug 01 04:00:00 EDT 1981 · Radiat. Res.; (United States)

DOI:https://doi.org/10.2307/3575583· OSTI ID:6314866

Koch, C J; Howell, R L

Experiments have been done to test whether a hypoxic cell radiosensitizing agent (misonidazole) can be combined with a radioprotecting agent (cysteamine) to equalize partially the radiation response of hypoxic and aerobic mammalian cells in tissue culture. The results indicate that cysteamine will protect against the radiosensitization of a hypoxic cell sensitizing drug (2.5 mM misonidazole) at much lower concentration than it will protect against the radiosensitization of oxygen (350 ..mu..M). Thus the addition of a radiation-protective drug tends to cancel the drug benefit of the radiosensitizer and therefore increases the differential response of hypoxic and aerobic cells rather than equalizing this response. The data suggest that even in situations where tumor tissue absorbs far less radioprotective drug than normal tissue (e.g., WR 2721), one might expect difficulties with the simultaneous administration of radiosensitizing and radioprotecting drugs.

• Research Organization: Cross Cancer Inst., Edmonton, Alberta
• OSTI ID: 6314866
• Journal Information: Radiat. Res.; (United States), Journal Name: Radiat. Res.; (United States) Vol. 87:2; ISSN RAREA
• Country of Publication: United States
• Language: English

Related Subjects

560121* -- Radiation Effects on Cells-- External Source-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AMINES
ANIMAL CELLS
ANIMALS
ANOXIA
ANTINEOPLASTIC DRUGS
AZOLES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CALCULATION METHODS
COBALT 60
COBALT ISOTOPES
CONNECTIVE TISSUE CELLS
DRUGS
ELECTROMAGNETIC RADIATION
ELEMENTS
FIBROBLASTS
GAMMA RADIATION
HAMSTERS
HETEROCYCLIC COMPOUNDS
IMIDAZOLES
IN VITRO
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
IONIZING RADIATIONS
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
MAMMALS
MEA
MINUTES LIVING RADIOISOTOPES
MISONIDAZOLE
NONMETALS
NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC SULFUR COMPOUNDS
OXYGEN
RADIATIONS
RADIOISOTOPES
RADIOPROTECTIVE SUBSTANCES
RADIOSENSITIVITY EFFECTS
RADIOSENSITIZERS
RESPONSE MODIFYING FACTORS
RODENTS
SOMATIC CELLS
SURVIVAL CURVES
THIOLS
VERTEBRATES
YEARS LIVING RADIOISOTOPES