Oxidation of heme proteins as a measure of oxidative damage to liver tissue slices.

Oxidative damage to heme proteins in rat liver tissue slices was studied. Tissue slices were incubated in Krebs-Ringer phosphate (KRP) buffer at 37 degrees C with and without the presence of prooxidants. The absorbance spectra (500-640 nm) of heme proteins of tissue slices obtained from both spontaneous and prooxidant-induced oxidation were analyzed with a heme protein spectra analysis program (HPSAP) developed in this laboratory. The dominant heme proteins in a fresh nonperfused tissue slice were hemoglobin and reduced cytochromes of mitochondria. In an oxidized tissue slice, the major oxidized product was hemichrome. Bromotrichloromethane, t-butyl hydroperoxide, and ferrous ion accelerated the oxidative reactions, and the amount of oxidized products was dependent on the incubation time as well as the type and concentration of prooxidants.