Assessment of the C-525 laser dye as a chemiluminescence sensitizer for lipid peroxidation in biological membranes: a comparison with chlorophyll-a.
The C-525 laser dye at micromolar concentration range is shown to enhance up to two to three orders of magnitude the chemiluminescence (CL) accompanying tert-butyl hydroperoxide (t-BHP)-induced rat liver microsome oxidation and Fe(2+)-induced lipid peroxidation (LPO) in liposomes. C-525 is shown to be a more efficient sensitizer of CL accompanying LPO in membrane systems than the known low-energy excited triplet carbonyl sensitizer, chlorophyll-alpha, (Cl-a). Regarding the sensitization mechanism, C-525 and Cl-a were compared in (a) a peroxyl radical-producing system (2,2'-azobis(2-dimethylvaleronitrile) (AMVN); (b) excited carbonyl-producing systems (3-hydroxymethyl-3,4,4-trimethyl-1,2-dioxetane (HTMD) thermal decomposition and horseradish peroxidase (HRP)-catalyzed isobutanal oxidation); and (c) excited singlet oxygen-producing system [endoperoxide of 3,3-(1,4-naphthylidene)-dipropionate (NDPO2)]. C-525 sensitized CL only in the systems where peroxyl radical and/or triplet excited carbonyls are produced, the mechanism of CL sensitization apparently is energy transfer from the excited triplet carbonyls formed in the peroxyl radical self-reaction via Russell's mechanism or by dioxetane decomposition. Cl-a was found to considerably sensitize CL related to NDPO2 thermal decomposition, a source of singlet oxygen, in addition to acting as a sensitizer of triplet carbonyl CL. The chemical stability of the C-525 laser dye in excited state-generating systems was shown to be appropriate for its application as a sensitizer of CL related to LPO reactions in membranes, but not in the HRP-catalyzed peroxidation system.
Institut für Physiologische Chemie I, Heinrich-Heine-Universität Düsseldorf, Germany.
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Sharov
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Briviba
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D000447:Aldehydes / Q000378:metabolism; D000818:Animals; D001391:Azo Compounds / Q000737:chemistry; D002734:Chlorophyll; D000077194:Chlorophyll A; D003374:Coumarins; D004355:Drug Stability; D005296:Ferrous Compounds / Q000494:pharmacology; D005456:Fluorescent Dyes; D005609:Free Radicals; D006571:Heterocyclic Compounds / Q000737:chemistry; D006735:Horseradish Peroxidase / Q000378:metabolism; D006358:Hot Temperature; D007700:Kinetics; D015227:Lipid Peroxidation / Q000187:drug effects; D008081:Liposomes / Q000378:metabolism; D008163:Luminescent Measurements; D008563:Membrane Lipids / Q000378:metabolism*; D008862:Microsomes, Liver / Q000378:metabolism; D009570:Nitriles / Q000737:chemistry; D010084:Oxidation-Reduction; D010545:Peroxides / Q000494:pharmacology; D011807:Quinolizines; D051381:Rats; D020122:tert-Butylhydroperoxide
C103833:3-hydroxymethyl-3,4,4-trimethyl-1,2-dioxetane; D000447:Aldehydes; D001391:Azo Compounds; C096706:C 525; D003374:Coumarins; D005296:Ferrous Compounds; D005456:Fluorescent Dyes; D005609:Free Radicals; D006571:Heterocyclic Compounds; D008081:Liposomes; D008563:Membrane Lipids; D009570:Nitriles; D010545:Peroxides; D011807:Quinolizines; C055792:2,2'-azobis(2,4-dimethylvaleronitrile); D002734:Chlorophyll; D020122:tert-Butylhydroperoxide; C017439:isobutyraldehyde; D006735:Horseradish Peroxidase; D000077194:Chlorophyll A