REDUCED OXYGEN ENHANCEMENT RATIO AT LOW-DOSES OF IONIZING-RADIATION
REDUCED OXYGEN ENHANCEMENT RATIO AT LOW-DOSES OF IONIZING-RADIATION
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DOI：
10.2307/3576354
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发表时间：
1984-01-01
影响因子：
3.4
通讯作者：
SKARSGARD, LD
中科院分区：
文献类型：
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作者：
PALCIC, B;SKARSGARD, LD
在较低的辐射剂量下，氧增强率(OER)降低已有报道(B.Palcic。等人的研究。1984年)。问题仍然是，这种影响是否归因于低剂量时可能存在的氧气污染，而高剂量时并非如此。以确保在开始照射前有足够程度的低氧。中国仓鼠细胞(CHO)采用37度气体交换结合氧代谢消耗的方法进行低氧处理。同时，使用克拉克电极测量细胞悬浮液中的O2水平。在本实验室用于低氧照射的实验条件下，开始照射前的O2水平始终低于可显著增强X射线辐射灭活的水平。用常规存活试验测定0-30Gy[灰色]剂量范围内的全生存曲线，用低剂量存活试验测定0-3Gy剂量范围内的全生存曲线。低剂量时OER降低。显然，剂量依赖的OER是一种真实的放射生物学现象，而不是低剂量存活试验中使用的实验方法的伪影。
A decreased oxygen enhancement ratio (OER) at lower radiation doses has been previously reported (B. Palcic. et al. 1984). The question remained whether or not this effect is due to a possible O2 contamination at low doses, which was not the case at high doses. To ensure a sufficient degree of hypoxia prior to the start of irradiation. Chinese hamster cells (CHO) were made hypoxic by gas exchange combined with metabolic consumption of O2 at 37.degree. C. At the same time O2 levels in cell suspension were measured using a Clark electrode. Under experimental conditions used in this laboratory for hypoxic irradiations, the O2 levels before the start of irradiation are always below the levels which could give any significant enhancement to radiation inactivation by X-rays. Full survival curves were determined in the dose range 0-30 Gy [gray] using the conventional survival assay and in the dose range 0-3 Gy using the low dose survival assay. The OER decreases at low doses. Apparently, the dose-dependent OER is a true radiobiological phenomenon and not an artifact of the experiment method used in the low dose survival assay.