Evidence for accumulation of lipid hydroperoxides during the aging of human red blood cells in the circulation

Young and old human red blood cells (RBC) were separated from freshly collected human blood by Percoll density gradient centrifugation. The amounts of lipid peroxidation products in the lipid fractions of these RBC were determined by high performance liquid chromatography-chemiluminescence, thiobarbituric acid and LPO-586 methods. The levels of phosphatidylcholine and phosphatidylethanolamine hydroperoxides in old RBC were higher than in young RBC. The products reflecting the advanced stage of lipid peroxidation, malonaldehyde (free and bound forms), 4-hydroxyalkenals (free and bound forms) and other aldehydes, were also higher in old RBC than in young RBC. The levels of these lipid peroxidation products increased when whole RBC were mildly oxidized with ferric ion. These results indicate that oxidative damage of RBC in the circulation takes place during the aging process, and lipid hydroperoxides and other lipid peroxidation products accumulate in old RBC.