Alloxan acts as a prooxidant only under reducing conditions: influence of melatonin

Depending on the availability of suitable reducing agents, alloxan can be either a prooxidant or an antioxidant. Alloxan and its reduced derivative, dialuric acid, act as a redox couple, driven by reduced glutathione (GSH) or L-cysteine, generating in vitro in the presence of oxygen, both superoxide...

Full description

Saved in:
Bibliographic Details
Published in:Cellular and molecular life sciences : CMLS 1999-03, Vol.55 (3), p.487-493
Main Authors: Brömme, H J, Ebelt, H, Peschke, D, Peschke, E
Format: Article
Language:English
Subjects:
Alloxan - antagonists & inhibitors
Alloxan - pharmacology
Alloxan - toxicity
Animals
Antioxidants
Antioxidants - pharmacology
Cellular biology
Chemiluminescence
Colorimetry
Free Radical Scavengers - pharmacology
Free radicals
Glutathione - metabolism
Hydrogen peroxide
Hydrogen Peroxide - metabolism
Imidazoles - metabolism
Islets of Langerhans - cytology
Islets of Langerhans - drug effects
Luminescent Measurements
Melatonin - pharmacology
Nitroblue Tetrazolium
Oxidants - antagonists & inhibitors
Oxidants - pharmacology
Oxidation-Reduction
Oxidative Stress
Oxygen
Reactive Oxygen Species
Superoxides - metabolism
Citations: Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Depending on the availability of suitable reducing agents, alloxan can be either a prooxidant or an antioxidant. Alloxan and its reduced derivative, dialuric acid, act as a redox couple, driven by reduced glutathione (GSH) or L-cysteine, generating in vitro in the presence of oxygen, both superoxide radical and hydrogen peroxide. The production of superoxide radicals was shown by the appearance of lucigenin chemiluminescence (CL) as well as by the generation of formazan from nitroblue tetrazolium (NBT). The lucigenin CL as well as the NBT reduction was inhibited by superoxide dismutase and partially by catalase. Melatonin inhibited alloxan-mediated CL. In contrast, in the absence of reducing agents, alloxan is a scavenger of superoxide radicals formed by other reactions. Because of the high content of reducing compounds in the cell (e.g. glutathione), it is suggested that alloxan acts in vivo mainly as a generator of reactive oxygen species.
ISSN:1420-682X
1420-9071
DOI:10.1007/s000180050305