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Origin, enzymatic pathways of reactive oxygen species, and their oxidized products. |
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| [Origin and Location] Enzymatic Pathways: |
[ROS] Potent Oxidants: |
[Products] Oxidized lipids and proteins: |
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| Mitochondrial Respiratory Chain |
O2• -OH• |
Oxidized lipids, proteins, nucleic acids, and autoxidation byproducts |
| Inflammatory Macrophage Membranous NAD(P)H Oxidase |
O2• -OH• H2O2 |
Advanced lipoxidation endproducts (ALE) ortho o-tyrosine meta m-tyrosine |
| Granular Myeloperoxidase (MPO) |
Hypochlorous acid HOCL Tyr (Tyrosine) NO2 |
3-Chlorotyrosine di-Tyrosine NO2-(Nitrotyrosine) |
| Macrophage |
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| Nitric Oxide Synthase (iNOS) Inducible (iNOS) Large bursts – uncontrolled |
ONOO• |
NO2-(Nitrotyrosine) |
| Endothelial Cell |
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| Nitric Oxide Synthase (NOS) Constitutive (cNOS) eNOS → NO nNOS → NO Small bursts – controlled |
NO + O2• → ONOO• ONOO• |
NO2-(Nitrotyrosine) NO2-(Nitrotyrosine) |
| eNOS-derived NO |
NO The GOOD * |
Natural-occurring, local-occurring, chain-breaking, antioxidant |
| Superoxide |
O2• The BAD * |
Toxic effects of ROS on proteins, lipid, nucleic acids |
| Peroxynitrite |
ONOO• The UGLY * |
Toxic effects of ROS on proteins, lipid, nucleic acids |
| Hypochlorous acid |
HCLO The UGLY * |
Toxic effects of ROS on proteins, lipid, nucleic acids |
| Restoration of eNO Via the eNOS reaction |
Antioxidant Antioxidant |
Prevention of the toxic effects of ROS |
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* Beckman JS and Koppenol WH [1996] Nitric oxide, superoxide, and peroxynitrite: the good, the bad, and ugly. Am J Physiol 271(5 Part 1): C1424–C1437 | ||
Hayden and Tyagi Nutrition & Metabolism 2004 1:10 doi:10.1186/1743-7075-1-10 |
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