Hydrogen peroxide in human blood.

Blood and plasma of humans and rats were analyzed for hydrogen peroxide. The samples were analyzed after deproteinization with trichloroacetic acid, immediately after they were withdrawn from human volunteers or rats. A radio-isotopic technique based on peroxide-dependent decarboxylation of 1-14C-alpha-ketoacids and consequent liberation of 14CO2 was used. The results demonstrate the presence of micromolar levels of H2O2, both, in the plasma as well as in the whole blood. The values in the whole blood were substantially greater than the plasma. This was true for rats as well as humans. The presence of such significant quantities of H2O2 in the blood have been demonstrated for the first time. The investigation, therefore, opens a newer avenue of research on diseases purported to be related to the generation of oxygen radicals in vivo.