H2O2Formation During Nucleotide Degradation in the Hypoxic Rat Liver: a Quantitative Approach

Abstract
In the hypoxic liver an increased rate of cytosolic and peroxisomal H2O2 generation is due to the accelerated purine nucleotide degradation. The relative contribution of the oxidase type of xanthine oxidoreductase activity increases in hypoxia by less than 10%, the dehydrogenase type of this enzyme is hardly inhibited by the increased concentration of free NADH. Nevertheless, due to the high hypoxanthine supply the xanthine oxidase related H2O2 formation is increased six-fold and together with the peroxisomal uricase-mediated share it accounts for half of the oxygen consumption.