OXIDATIVELY MODIFIED PLASMA PHOSPHOLIPIDS CONTAINING REACTIVE CARBONYL FUNCTIONS MEASURED BY HPLC - EVIDENCE FOR PHOSPHATIDYLCHOLINE-BOUND ALDEHYDES IN PLASMA OF BURN PATIENTS

A HPLC method has been developed to measure phosphatidylcholine (PC) c ontaining reactive carbonyl functions in the sn-acyl residue in order to study processes in which such reactive carbonyls can be formed due to e.g. oxidative fragmentation. The method has been applied to determ ine PC-bound carbonyls as 2,4-dinitrophenylhydrazones (DNPH) in plasma of burn patients. Plasma from healthy volunteers served as controls. Additionally, in vitro oxidation experiments (A: plasma, buffer dilute d; B: plasma + iron-EDTA complex and C: plasma + iron-EDTA complex + H 2O2) have been performed to obtain and to identify 2,4-dinitrophenylhy drazine derivatizable carbonyl functions in plasma PC. Both, the PC-al dehydes and PC-aldehyde DNPH derivatives were cleavable with phospholi pase C. Quantification was based on thin-layer chromatography purified soybean phosphatidylcholine, which was identically oxidized and deriv atized as the plasma lipids in vitro.