Amplification of glutathione-mediated oxidative stress by catalase in an aqueous solution at hyperthermal temperatures.

The glutathione (GSH)-mediated superoxide (O2•-) generation in an aqueous solution and relation of hydrogen peroxide (H2O2) and effect of catalase were investigated. GSH-induced O2•- generation in hyperthermal temperatures was measured by the nitroblue tetrazolium (NBT) mehod. Heating an aqueous solution containing GSH caused superoxide from dissolved O2. H2O2 was generated simultaneously in this reaction mixture probably from the hydroperoxy radical (HO2•), which is equilibrated with O2•- in an aqueous condition, and then H2O2 consumed O2•-. Coexisting catalase in the reaction mixture, as a result, could increase O2•- generation. The catalase-exaggerated extracellular O2•- generation could give a harmful effect to living cells. This GSH-induced oxidative stress can be a part of mechanisms of hyperthermia therapy.