In vitro phosphatidylcholine peroxidation mediated by activated human neutrophils.
Activated human polymorphonuclear leukocytes (PMNs) mediated peroxidation of dilinoleoyl phosphatidylcholine (DPLC) liposomes. Concentration-response effects were demonstrated for both PMNs and DLPC in the system studied. Chelated iron facilitated peroxidation threefold. Superoxide dismutase variably inhibited peroxidation, but never completely. Although O2-. synthesis ceased 30-40 min after PMN stimulation, lipid peroxidation continued for an additional 30-60 min, suggesting that PMNs may initiate peroxidation which subsequently becomes autocatalytic. Enhanced PMN-mediated DLPC peroxidation was noted in acidic media. Separation of DLPC reaction products by high pressure liquid chromatography demonstrated the de novo appearance of conjugated diene species. Preliminary specific ion monitoring mass spectroscopy analysis of gas chromatography fractions of reaction products (derivatized to fatty acid methyl esters/trimethylsilane hydroxyl ethers) indicated that PMN-generated oxyradicals resulted in production of conjugated 9- and 13-hydroperoxy DLPC derivatives. These results illustrate directly how activated PMNs may participate in host autoinjury by mediating phospholipid peroxidation.
Zimmerman
J J
JJ
Division of Critical Care Medicine, University of Wisconsin Children's Hospital, Madison.
Lewandoski
J R
JR
D004305:Dose-Response Relationship, Drug; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008054:Lipid Peroxides / Q000378:metabolism*; D009504:Neutrophils / Q000378:metabolism*; D009994:Osmolar Concentration; D010713:Phosphatidylcholines / Q000378:metabolism*
D008054:Lipid Peroxides; D010713:Phosphatidylcholines; C002448:1,2-linoleoylphosphatidylcholine