Excretion of hydrogen peroxide in human urine

The excretion of hydrogen peroxide in human urine has been demonstrated for the first time. This was accomplished by a new radioactive method developed on the basis of decarboxylation of alpha-ketoglutaric acid by H2O2. Urine samples were incubated with alpha ketoglutarate pulsed with iwts 1-14C-analogue, and CO2 formed by decarboxylation was determined by radioactivity measurements. Blanks were prepared by pre-incubation of the samples with catalase. Both male and female subjects were studied. On an average the concentration of H2O2 in urine was approximately 100 +/- 60 microM (10(-4) M). Peroxide excretion was found to be unexpectedly high and might thus be useful for clinical diagnosis and therapy in diseases purported to be related to oxidative stress.