Status of glutathione in the rat liver. Enhanced formation of oxygen radicals at low oxygen tension.

Rat livers were initially perfused and then stored at various temperatures up to 4 h. The intra- and extrahepatic status of glutathione, the accumulation of hydrogen peroxide in the preservation medium, the action of a OH-scavenger and of a xanthine oxidase-inhibitor were investigated as candidates for the assessment of oxidative alterations due to ischemia. Furthermore respiratory functions of mitochondria were measured. The increased efflux of GSSG from the liver tissue, the increase of the GSSGtot/GSHtot-ratio and the favourable effects of formate as OH-scavenger and of allopurinol as xanthine oxidase-inhibitor confirm the hypothesis about the oxidative damage under conditions of oxygen deficiency. The nucleotide degradation, especially the steps catalyzed by xanthine oxidase and uricase, is the main metabolic pathway for the generation of oxygen radicals under ischemic conditions.