title: Stimulus-specific enhancement of luminol chemiluminescence in neutrophils by phosphatidylserine liposomes.
abstract: When stimulated with different stimuli, neutrophils generate various active oxygen species. These active oxygen molecules can be analyzed by luminol chemiluminescence (LCL). Phosphatidylserine (PS)-liposomes increased the formylmethionyl-leucyl-phenylalanine-induced LCL of guinea pig peritoneal neutrophils without affecting their oxygen consumption and superoxide (O2.-) generation. Similar effects of PS-liposomes were also observed in LCL of neutrophils stimulated by phorbol myristate acetate or arachidonic acid but not by opsonized zymosan. Kinetic analysis revealed that the PS-liposome-induced increase in LCL depended on extracellulary generated O2.-. Moreover, the stimulatory effect of PS could be seen only when it formed liposomal membranes. The effect of PS-liposomes was also inhibited by superoxide dismutase, catalase, and deferoxamine, an iron chelator, but not by azide, an inhibitor of myeloperoxidase. Similar enhancement of stimulation-dependent LCL response was also observed with Fe3+ and ADP-Fe3+, but the degree of enhancement was much greater with PS-liposomes than with iron and its complex. The increase in hydroxyl radical generation by PS-liposome-treated neutrophils was confirmed by experiments with EPR spectrometry using spin-trapping agents. These results suggested that the interaction of neutrophils with PS-containing membrane surface might generate reactive oxygen species that enhance the stimulus-dependent LCL response of neutrophils.
authors.affiliation: Department of Neuropsychiatry, Kochi Medical School, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Takahashi
authors.forename: H
authors.initials: H
authors.lastname: Ikeda
authors.forename: E F
authors.initials: EF
authors.lastname: Sato
authors.forename: K
authors.initials: K
authors.lastname: Akimaru
authors.forename: R
authors.initials: R
authors.lastname: Edamatsu
authors.forename: M
authors.initials: M
authors.lastname: Inoue
authors.forename: K
authors.initials: K
authors.lastname: Utsumi
mesh_terms: D000818:Animals; D002374:Catalase / Q000494:pharmacology; D003676:Deferoxamine / Q000494:pharmacology; D004578:Electron Spin Resonance Spectroscopy; D005609:Free Radicals; D006168:Guinea Pigs; D008081:Liposomes / Q000737:chemistry; D008163:Luminescent Measurements; D008165:Luminol / Q000737:chemistry*; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D009504:Neutrophils / Q000502:physiology*; D010100:Oxygen / Q000737:chemistry*; D010718:Phosphatidylserines / Q000737:chemistry / Q000502:physiology*; D016897:Respiratory Burst; D015398:Signal Transduction; D013482:Superoxide Dismutase / Q000494:pharmacology
chemical_list: D005609:Free Radicals; D008081:Liposomes; D010718:Phosphatidylserines; D009240:N-Formylmethionine Leucyl-Phenylalanine; D008165:Luminol; D002374:Catalase; D013482:Superoxide Dismutase; D003676:Deferoxamine; D010100:Oxygen