Irradiation of mammalian cells in the presence of diamide and low concentrations of oxygen at conventional and at ultrahigh dose rates

Journal Article · Tue Mar 01 04:00:00 EST 1983 · Radiat. Res.; (United States)

DOI:https://doi.org/10.2307/3576027· OSTI ID:5682852

Clark, E P; Michaels, H B; Peterson, E C; Epp, E R

The response of cultured CHO cells to ultrahigh-dose-radiation (approx.10/sup 9/ Gy/sec) has been previously studied extensively using the thin-layer cell-handling technique developed in this laboratory. When the cells are equilibrated with a low concentration of oxygen, e.g., 0.44% O/sub 2/, a breaking survival curve, due to radiolytic depletion of the oxygen, is observed. Hypoxic cells irradiated in the presence of the nitroimidazoles (e.g., misonidazole) are sensitized at ultrahigh dose rates in a dose-modifying manner, similar to that observed at conventional dose rates. These radiosensitizer compounds, if present in cells equilibrated with a low concentration of oxygen, prevent the breaking behavior of the survival curve, an observation believed to be due to the sensitizer interfering with the oxygen depletion process, leaving oxygen free to sensitize. Such experiments have recently been extended to studies with diamide, which, unlike the other sensitizers tested, acts primarily as a shoulder-modifying rather than a dose-modifying agent in hypoxic mammalian cells. These data indicate that diamide is active as a sensitizer at ultrahigh dose rates in a manner similar to that observed at conventional dose rates, and does modify the shape of the breaking survival curve observed with low concentrations of oxygen.

• Research Organization: Harvard Medical School, Boston, MA
• OSTI ID: 5682852
• Journal Information: Radiat. Res.; (United States), Journal Name: Radiat. Res.; (United States) Vol. 93:3; 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.
ANIMAL CELLS
ANTINEOPLASTIC DRUGS
AZOLES
BIOLOGY
CHO CELLS
DOSE RATES
DRUGS
ELECTROMAGNETIC RADIATION
ELEMENTS
HETEROCYCLIC COMPOUNDS
IMIDAZOLES
IONIZING RADIATIONS
MISONIDAZOLE
NONMETALS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXYGEN
RADIATIONS
RADIOBIOLOGY
RADIOSENSITIVITY
RADIOSENSITIVITY EFFECTS
RADIOSENSITIZERS
SURVIVAL CURVES
X RADIATION