Basu-Modak S, Tyrrell R M
Swiss Institute for Experimental Cancer Research, Physical Carcinogenesis Unit, Epalinges/Lausanne.
Cancer Res. 1993 Oct 1;53(19):4505-10.
Both singlet oxygen and the hydroxyl radical are generated in mammalian cells by UVA (320-380 nm) and possibly near-visible (380-420 nm) radiation. We have modulated the cellular levels of these two reactive oxygen species in order to compare their involvement in the induction of the human heme oxygenase (HO) gene by broad spectrum UVA/near-visible light (UVA/NVL). Irradiation in deuterium oxide (in which singlet oxygen has a longer half-life) enhances the broad spectrum UVA/NVL induction of this gene. Sodium azide and L-histidine which are scavengers of both singlet oxygen and the hydroxyl radical reduce the fluence-dependent accumulation of HO mRNA, while compounds which are only hydroxyl radical scavengers, namely, mannitol and dimethyl sulfoxide do not. Rose Bengal, a known generator of singlet oxygen, also increases the HO mRNA levels, and this induction is enhanced in deuterium oxide. We conclude that the observed effects of deuterium oxide and singlet oxygen scavengers on HO mRNA levels are not due to a nonspecific effect on transcription but that singlet oxygen is a primary effector in the UVA/NVL induction of the human heme oxygenase gene.
在哺乳动物细胞中，单线态氧和羟基自由基可由紫外线A（320 - 380纳米）以及可能的近可见光（380 - 420纳米）辐射产生。我们已对这两种活性氧物质的细胞水平进行调节，以便比较它们在广谱紫外线A/近可见光（UVA/NVL）诱导人类血红素加氧酶（HO）基因过程中的作用。在重水中进行辐照（单线态氧在其中半衰期更长）可增强该基因的广谱UVA/NVL诱导作用。叠氮化钠和L - 组氨酸作为单线态氧和羟基自由基的清除剂，可降低HO mRNA的光通量依赖性积累，而仅作为羟基自由基清除剂的化合物，即甘露醇和二甲基亚砜则不会。孟加拉玫瑰红作为一种已知的单线态氧生成剂，也会增加HO mRNA水平，且在重水中这种诱导作用会增强。我们得出结论，重水和单线态氧清除剂对HO mRNA水平的观察到的影响并非由于对转录的非特异性作用，而是单线态氧是UVA/NVL诱导人类血红素加氧酶基因的主要效应物。
