Increase in fragmented phosphatidylcholine in blood plasma by oxidative stress

Oxidatively modified phospholipids with fragmented acyl chains have attract ed much interest because of their proinflammatory activity and their potent ial involvement in atherosclerosis. They can be formed in vitro by free rad ical treatment of unsaturated phospholipids but it is not known under which conditions they accumulate in vivo. We assayed one species of fragmented p hosphatidylcholine (PC) in human blood plasma by high performance liquid ch romatography after precolumn derivatization with chloromethylanthracene. St ructural analysis suggested that fragmented PC was a diacyl species with a palmitoyl group and a short oxidized residue, which most likely had four ca rbons. The concentration of fragmented PC was higher in elderly individuals with coronary heart disease than in young healthy controls. Smoking one ci garette acutely increased the concentration of fragmented PC in healthy adu lts. Fragmented PC also increased in the reperfusion period after treatment with cardiopulmonary bypass. The increase coincided with a surge of circul ating neutrophils. In rats, the plasma concentration of fragmented PC was e levated by vitamin E deficiency and exposure to high oxygen. The data demon strate that fragmented PC increases in blood plasma in response to various forms of oxidative stress.