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Peroxynitrite-induced luminol chemiluminescence
R Radi1, T P Cosgrove, J S Beckman
1Department of Anesthesiology, University of Alabama, Birmingham 35233-6810.
The Biochemical Journal
|February 15, 1993
Summary
Peroxynitrite anion (ONOO-), generated by various cells, significantly enhances luminol chemiluminescence, especially with bicarbonate. Superoxide anion (O2.-) is crucial for this light emission, suggesting ONOO- as a key mediator in cell-derived chemiluminescence.
Area of Science:
- Biochemistry
- Cell Biology
- Oxidative Stress Research
Background:
- Diverse cell types produce superoxide (O2.-) and nitric oxide (.NO).
- Superoxide and nitric oxide react to form peroxynitrite anion (ONOO-), a potent oxidant.
- Cell-derived luminol chemiluminescence has been previously reported.
Purpose of the Study:
- To investigate the role of peroxynitrite anion (ONOO-) in luminol chemiluminescence.
- To elucidate the mechanism of ONOO--induced chemiluminescence.
- To determine the influence of bicarbonate on ONOO- reactions.
Main Methods:
- Studying the reaction of peroxynitrite with luminol in the presence of bicarbonate.
- Measuring chemiluminescence quantum yield.
- Utilizing superoxide dismutase to assess the role of superoxide anion (O2.-).
Main Results:
- Peroxynitrite reacted with luminol to produce enhanced chemiluminescence, significantly amplified by bicarbonate.
- The quantum yield for the ONOO--luminol reaction in bicarbonate was approximately 10(-3).
- Chemiluminescence was inhibited by superoxide dismutase, confirming O2.- as a key intermediate.
Conclusions:
- Peroxynitrite anion (ONOO-) is a critical, previously unrecognized mediator of cell-derived luminol chemiluminescence.
- Superoxide anion (O2.-) is essential for the chemiexcitation process.
- Bicarbonate participates in secondary oxidation reactions involving ONOO-.