Brandi G, Sestili P, Pedrini M A, Salvaggio L, Cattabeni F, Cantoni O
Mutat Res. 1987 Apr;190(4):237-40. doi: 10.1016/0165-7992(87)90002-9.
The cytotoxicity of hydrogen peroxide in Escherichia coli was investigated after various conditions of drug exposure. Two modes of killing were detected following a 15-min challenge with H2O2 under either aerated or anoxic conditions. Mode one killing occurred at levels below 2.5 mM and mode two killing at concentrations higher than 10 mM. Whereas mode one killing was similar at the two conditions of drug exposure, mode two lethality differed in that aerated cells were more sensitive than anoxic cells. Independently of O2 tension the hydroxyl radical scavenger, thiourea, prevented mode two but not mode one killing by H2O2. Cells treated with the drug at ice temperature did not display mode one killing and mode two lethality occurred only at very high concentrations. We suggest that hydroxyl radicals mediate mode two but not mode one killing by H2O2.
在不同药物暴露条件下，对过氧化氢在大肠杆菌中的细胞毒性进行了研究。在有氧或缺氧条件下用H2O2处理15分钟后，检测到两种杀伤模式。第一种杀伤模式发生在低于2.5 mM的水平，第二种杀伤模式发生在高于10 mM的浓度。虽然第一种杀伤模式在两种药物暴露条件下相似，但第二种杀伤模式的致死率有所不同，即有氧细胞比缺氧细胞更敏感。与氧气张力无关，羟基自由基清除剂硫脲可阻止H2O2的第二种杀伤模式，但不能阻止第一种杀伤模式。在冰温下用该药物处理的细胞未表现出第一种杀伤模式，第二种致死性仅在非常高的浓度下才会出现。我们认为羟基自由基介导了H2O2的第二种杀伤模式，而不是第一种杀伤模式。
