Studies on the mechanism of toxicity of the mycotoxin sporidesmin 3—inhibition by metals of the generation of superoxide radical by sporidesmin
✍ Scribed by R. Munday
- Publisher
- John Wiley and Sons
- Year
- 1984
- Tongue
- English
- Weight
- 490 KB
- Volume
- 4
- Category
- Article
- ISSN
- 0260-437X
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✦ Synopsis
Abstract
The mycotoxin sporidesmin has previously been shown to generate superoxide radical. This reaction involves autoxidation of the reduced form of the mycotoxin, a dithiol. In the present study, a number of mercaptide‐forming metals have been shown to inhibit superoxide formation from sporidesmin in vitro. Furthermore, these metals decreased the rate of sporidesmin‐induced hydrogen peroxide formation in erythrocytes and ameliorated the subsequent oxidative damage to these cells. These effects were found to be specific to sporidesmin; mercaptide‐forming metals did not inhibit the changes induced by compounds which are not dependent upon thiol groups for active oxygen generation. Zinc was one of the most potent inhibitors of superoxide generation from sporidesmin in these test systems; only mercury and cadmium were significantly more active. Salts of zinc are known to provide effective protection against the harmful effects of sporidesmin in vivo. The results of these studies provide a possible explanation for this effect.
📜 SIMILAR VOLUMES
Sporidesmin, the mycotoxin responsible for 'facial eczema' in ruminants, has previously been shown to generate superoxide radical and hydrogen peroxide. In the present study, the formation of the third 'active oxygen' species, hydroxyl radical, has been demonstrated. This species is produced both du
Formation of hydrogen peroxide, the dismutation product of superoxide radical, has been demonstrated in erythrocytes incubated with the mycotoxin sporidesmin. Erythrocytic thiols, both non-protein and protein-bound, were depleted in the presence of sporidesmin, whilst haemoglobin was oxidized to met