Mechanism of ochratoxin A stimulated lipid peroxidation.
Biochem Pharmacol
; 40(6): 1183-91, 1990 Sep 15.
Article
em En
| MEDLINE
| ID: mdl-2119584
ABSTRACT
Lipid peroxidation, measured as malondialdehyde formation or by oxygen uptake, was stimulated markedly by the mycotoxin ochratoxin A (OTA) in a reconstituted system consisting of phospholipid vesicles, the flavoprotein NADPH-cytochrome P450 reductase, Fe3+, EDTA and NADPH. Deletion of EDTA lowered the extent of lipid peroxidation but did not eliminate it. Fluorometric and spectrophotometric studies demonstrated the formation of a 11 Fe3(+)-OTA complex. The rate of reduction of Fe3+ to Fe2+ was enhanced markedly in the presence of OTA, and there was a further increase in the rate when EDTA was also included. The data indicate that OTA stimulates lipid peroxidation by complexing Fe3+ and facilitating its reduction. Subsequent to oxygen binding, an iron-oxygen complex of undetermined nature initiates lipid peroxidation. Free hydroxyl radicals appear not to participate in lipid peroxidation stimulated by Fe3(+)-OTA.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Microssomos Hepáticos
/
Peroxidação de Lipídeos
/
Ferro
/
Ocratoxinas
Limite:
Animals
Idioma:
En
Revista:
Biochem Pharmacol
Ano de publicação:
1990
Tipo de documento:
Article
País de afiliação:
Canadá