The Measurement of Conjugated Dienes in Ischemic and Reperfused Myocardium

Abstract

When we began toying with the idea of attempting to measure a chemical marker in myocardium which was indicative of oxygen free radical attack or oxidative stress a variety of analytical options were open to us. These included a) spin trapping primary species such as superoxide and hydroxyl radicals or other secondary radical species(1) b) assay of malonyldialdehyde either with thiobarbituric acid or by direct HPLC spectrophotometric analysis(2) c) assay of lipid hydroperoxide species by fluorescent or luminescent assays(3) d) measurement of pentanes and ethanes(4) e) detection of water soluble polyunsaturated fatty acid oxidation and fragmentation products (ie. hydroxyalkenals) (5) f) detecting a decrease in protein or peptide sulfhydryl redox state (6) g) measuring amino acid oxidation in protein (7) h) conjugated diene formation (8) i) chemiluminescent light emission due to the formation of activated oxygen species (9). Clearly at least two major molecular components of cells were demonstrably susceptible to oxidative attack by free radical species; namely polyunsaturated fatty acyl moeities of phospholipid and sulfur containing amino acid residues in protein. Other amino acids have also been shown to be susceptible to free radical and oxidative attack (tyrosine, histidine, etc.) (10).