Abstract:
:The effect of hypoxia on the induction of and recovery from damage by radiation alone and in combination with heat has been investigated using plateau-phase Chinese hamster ovary (CHO) cells. Postirradiation hypoxia reduced the potentially lethal damage recovery (PLDR) in cells irradiated under an euoxic state and completely eliminated PLDR in cells irradiated under hypoxia. Cells which were maintained under hypoxia during both irradiation and a 4-hr recovery period and then incubated for a further period of 4 hr under euoxic conditions showed PLDR, suggesting that the inhibition of PLDR by hypoxia is reversible. Oligomycin, an inhibitor of energy metabolism, completely eliminated PLDR when present at a concentration of 1 microM during the postirradiation period. Pre- or postirradiation heat treatment at 42.5 degrees C for 30 min appreciably sensitized the cells to the induction of lethality. Thermal enhancement ratio (TER) was 1.7 for cells irradiated and heat treated under hypoxic conditions. The same heat treatment reduced the oxygen enhancement ratio (OER) associated with gamma radiation from 3.1 to 2.5. Cells subjected to this postirradiation heat treatment showed a small extent of PLDR, whereas the pre-heat-treated cells showed as much recovery as non-heat-treated cells. When hypoxic conditions prevailed during the post-treatment incubation period, PLDR was reduced in preheated cells and completely eliminated in postheated cells. The kinetics of interaction between heat and radiation damage were studied by introducing a time gap of 4 hr between the treatments. Cells maintained under euoxic conditions between the treatments showed an appreciable decrease in interaction, suggesting recovery from damage induced by the first treatment. Hypoxic conditions intervening the two treatments largely inhibited the loss of sensitization. Analysis of the results suggests that cells fail to recover from sublethal heat damage when held for 4 hr under hypoxic conditions. Cells held under hypoxic conditions partly recover from the radiation damage which subsequently interacts with sublethal heat damage, resulting in cell lethality.
journal_name
Radiat Resjournal_title
Radiation researchauthors
Rao BS,Hopwood LEsubject
Has Abstractpub_date
1985-02-01 00:00:00pages
312-25issue
2eissn
0033-7587issn
1938-5404journal_volume
101pub_type
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journal_title:Radiation research
pub_type: 杂志文章
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更新日期:2011-06-01 00:00:00
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journal_title:Radiation research
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journal_title:Radiation research
pub_type: 杂志文章
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更新日期:1997-07-01 00:00:00
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journal_title:Radiation research
pub_type: 杂志文章
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更新日期:2002-10-01 00:00:00
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journal_title:Radiation research
pub_type: 杂志文章
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更新日期:1997-04-01 00:00:00
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pub_type: 杂志文章
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更新日期:2015-02-01 00:00:00
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journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1985-01-01 00:00:00
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journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1990-03-01 00:00:00
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journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1999-08-01 00:00:00
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journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1995-03-01 00:00:00
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journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1990-09-01 00:00:00
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journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1996-10-01 00:00:00
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journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/RR15328.1
更新日期:2019-06-01 00:00:00
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journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/RR1414.1
更新日期:2008-12-01 00:00:00
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journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1984-03-01 00:00:00
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journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/RR14666.1
更新日期:2017-08-01 00:00:00
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pub_type: 杂志文章
doi:10.1667/r3016
更新日期:2003-07-01 00:00:00
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journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1990-08-01 00:00:00
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journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1983-04-01 00:00:00
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journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1983-12-01 00:00:00
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journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1968-12-01 00:00:00
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journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1997-02-01 00:00:00
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pub_type: 杂志文章
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journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/0033-7587(2003)159[0247:iocbbc]2.0.co;2
更新日期:2003-02-01 00:00:00
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journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/0033-7587(2003)159[0775:eotsmf]2.0.co;2
更新日期:2003-06-01 00:00:00
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journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1989-08-01 00:00:00
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journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/rr3191
更新日期:2004-08-01 00:00:00
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journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/RR3190.1
更新日期:2013-09-01 00:00:00
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journal_title:Radiation research
pub_type: 杂志文章
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更新日期:2005-10-01 00:00:00
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journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1988-06-01 00:00:00