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

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