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

Abstract

Oxidative damage to heme proteins in rat liver tissue slices was studied. Tissue slices were incubated in KrebsRinger phosphate (KRP) buffer at 37°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) development 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.