The radiation response of cells recovering after chronic hypoxia.
The radiation response of cells recovering after chronic hypoxia.
复制标题
慢性缺氧后细胞恢复的辐射反应。
作者：
T. Kwok;R. Sutherland
实验研究了低氧预处理对人鳞癌细胞A431辐射效应的影响。慢性低氧(>2 h)复氧10min可提高A431细胞的放射敏感性，其中以12 h复氧效果最好。缺氧12h后复氧细胞的放射增敏作用在复氧后5min达到最大，复氧12h时达到对照水平。这种增强的放射敏感性状态的特征是肩部区域减少，处于指数生长期和平台期的细胞的辐射剂量-反应曲线斜率增加。缺氧12h后，指数期和平台期细胞的G1期细胞数均略有增加，而S和G2+M期细胞数均略有减少。低氧12h对指数期细胞生长有抑制作用，但平台期细胞数无明显变化。缺氧后两个生长期细胞的培养效率(PE)均下降30%。此外，在指数期培养中，处于细胞周期不同时相的细胞在低氧后PE降低的程度相似。尽管指数生长期的S期细胞比G1和G2+M细胞对辐射的抗性更强，但无论细胞在复氧和照射前处于有氧还是缺氧状态，细胞的年龄-反应模式都是相同的。此外，在缺氧12小时后，与复氧相关的对这三种细胞亚群的增强比为1.3。我们的结果表明，慢性低氧后复氧引起的放射敏感性增加不太可能与低氧处理过程中细胞周期和生长期的变化有关。
Experiments were performed to study the influence of hypoxic pretreatment on the radiation response of A431 human squamous carcinoma cells. Reaeration for 10 min after chronic hypoxia (greater than 2 h) was found to enhance the radiosensitivity of A431 cells, and the maximal effect was seen for those cells reaerated after 12 h of hypoxia. The radiosensitivity enhancement for reaerated cells after 12 h of hypoxia was maximized by 5 min after the return to aerobic conditions and reached the control level by 12 h of reaeration. This enhanced radiosensitive state was characterized by a reduced shoulder region and increased slope of the radiation dose-response curve for cells in both the exponential and plateau phases of growth. There was a slight increase in the number of G1 and decrease in the number of S and G2 + M cells for both exponential- and plateau-phase cultures following 12 h hypoxic treatment. Although growth inhibition induced by 12 h of hypoxia was seen for cells in the exponential phase, there was no cell number change in the plateau-phase culture after hypoxia. Plating efficiency (PE) of cells in both growth phases was reduced by 30% after hypoxia. Furthermore, in the exponential-phase culture, the extent of reduction in PE after hypoxia was similar among cells in different phases of the cell cycle. Although S-phase cells in exponentially growing cultures were relatively more resistant to radiation than G1 and G2 + M cells, the cell age-response pattern was the same whether the cells had been aerobic or hypoxic before reaeration and irradiation. Furthermore, the enhancement ratio associated with reaeration after 12 h of hypoxia for these three subpopulations of cells was 1.3. Our results indicate that the increase in radiosensitivity due to reaeration after chronic hypoxia is unlikely to be related to the changes of cell cycle stage and growth phase during hypoxic treatment.
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通过预暴露于缺氧来防止氧气中毒：肺抗氧化酶的作用。
DOI：
10.1152/jappl.1982.53.2.475
发表时间：
1982
期刊：
Journal of applied physiology: respiratory, environmental and exercise physiology
影响因子：
--
作者：
Frank,L
通讯作者：
Frank,L
利用一氯代二胺通过流式细胞术定量分析细胞谷胱甘肽：在体外和体内辐射和耐药性方面的一些应用。
影响因子：
11.2
作者：
Rice,GC;Bump,EA;Shrieve,DC;Lee,W;Kovacs,M
通讯作者：
Kovacs,M
人鳞癌 A431 细胞辐射敏感性的表征。
影响因子：
8.8
作者：
Ng,CE;Keng,PC;Sutherland,RM
通讯作者：
Sutherland,RM
DOI：
10.1016/0360-3016(86)90155-0
发表时间：
1986
期刊：
International journal of radiation oncology, biology, physics
影响因子：
--
作者：
Heacock,CS;Sutherland,RM
通讯作者：
Sutherland,RM