Dose-rate effects on the cell cycle and survival of S3 HeLa and V79 cells
The effects of continuous irradiation at different dose rates on the cell cycle and on cell survival were studied using synchronized S3 HeLa and V79 cells. The minimum dose rate necessary to stop cell division was found to be approximately 23 rad/hr for HeLa cells and 270 rad/hr for V79 cells. For dose rates that stop cell division, cells progress through G/sub 1/ and S, with a small delay in the S phase, and are blocked in G/sub 2/. Appreciable mitotic accumulation was observed for HeLa cells at dose rates which stopped cell division. By comparison, much less mitotic accumulation was observed for V79 cells over a range of dose rates from 37 to 270 rad/hr. Minimum mitotic delays for a variety of dose rates were determined for both cell lines. S3 HeLa cells are much more sensitive in this respect than V79 cells; however, it appeared that for higher dose rates the minimum mitotic delay in HeLa cells asymptotically approached a value of about 35 hr. In addition to the qualitative differences observed for the two cell lines in regard to mitotic accumulation, HeLa cells accumulated for prolonged periods in the presence of colcemid while V79 cells were blocked for only a few hours, HeLa cells show a dramatic effect of redistribution of cells into sensitive phases of the cell cycle during exposure, which was reflected in the survival curves at low dose rate. More cell killing per unit dose was observed at 37 than at 74 rad/hr.
- Research Organization:
- Colorado State Univ., Fort Collins
- OSTI ID:
- 5758516
- Journal Information:
- Radiat. Res.; (United States), Vol. 79:3
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
CELL CYCLE
INHIBITION
CHRONIC IRRADIATION
BIOLOGICAL RADIATION EFFECTS
HELA CELLS
SYNCHRONOUS CULTURES
CELL KILLING
DOSE RATES
DOSE-RESPONSE RELATIONSHIPS
TRITIUM
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL EFFECTS
CELL CULTURES
CHRONIC EXPOSURE
HYDROGEN ISOTOPES
IRRADIATION
ISOTOPES
LIGHT NUCLEI
NUCLEI
ODD-EVEN NUCLEI
RADIATION EFFECTS
RADIOISOTOPES
YEARS LIVING RADIOISOTOPES
560121* - Radiation Effects on Cells- External Source- (-1987)