Role of Hydroxyl Radicals in Escherzchza Colz Killing Induced by Hydrogen Peroxide |
| |
| Authors: | Giorgio Brandi Flaminio Cattabeni Amedeo Albano Orazio Cantoni |
| |
| Affiliation: | a Instituto di Scienze Tossicologiche, Igienistiche e Ambientali, Universita' degli Studi di Urbino, Urbino, (Italy)b Istituto di Farmacologia e Farmacognosia and Centro di Farmacologia Oncologica Sperimentale, Universita' degli Studi di Urbino, Urbino, (Italy) |
| |
| Abstract: | Escherichia coli lethality by hydrogen peroxide is characterized by two modes of killing. In this paper we have found that hydroxyl radicals (OH -) generated by H2O2 and intracellular divalent iron are not involved in the induction of mode one lethality (i.e. cell killing produced by concentrations of H2O2 lower than 2.5 mM). In fact, the OH radical scavengers, thiourea, ethanol and dimethyl sulfoxide, and the iron chelator, desferrioxarnine, did not affect the survival of cells exposed to 2.5mM H2O2. In addition cell vulnerability to the same H2O2 concentration was independent on the intracellular iron content. In contrast, mode two lethality (i.e. cell killing generated by concentrations of H2O2 higher than 10mM) was markedly reduced by OH radical scavengers and desferrioxamine and was augmented by increasing the intracellular iron content.
It is concluded that OH. are required for mode two killing of E. coli by hydrogen peroxide. |
| |
| Keywords: | hydrogen peroxide hydroxyl radicals toxicity Escherichia coli |
| 本文献已被 InformaWorld 等数据库收录！ |
|
