title: Paraquat potentiates iron-induced microsomal lipid peroxidation: modulation by the diet lipid composition.
abstract: The study concerns the role of two combined factors-lipid composition of the microsomal membranes and the iron concentration in the incubation medium-in lipid peroxidation catalysed by paraquat (P(++)). Rats were subjected to diets containing 5% lipids composed of either tripalmitin (T), peanut oil/rapeseed oil (v/v) (C) or fish oil (F). The level of polyunsaturated fatty acids in the microsomal membranes was higher in C and F than in T. The level of vitamin E was lowest in F. The activity of the system 'Cyt P450-NADPH cyt c reductase' increased in the order T<C<F. The iron concentrations initiating a basal NADPH-dependent lipid peroxidation have been established. p(++) potentiates this peroxidation due to additional reduction of Fe(3+) by p(+.), rather than by O2(.-) as is usually thought to occur. The sensitivity of the membranes to the potentiating effect of P(+ +) is mainly determined by a high level of polyunsaturated fatty acids, but also by a low level of the antioxidant vitamin E.
authors.affiliation: a Laboratoire des Xénobiotiques , INRA, BP 3, Toulouse , France.
authors.forename: Y
authors.initials: Y
authors.lastname: Fernandez
authors.affiliation: a Laboratoire des Xénobiotiques , INRA, BP 3, Toulouse , France.
authors.forename: S
authors.initials: S
authors.lastname: Mitjavila
authors.affiliation: a Laboratoire des Xénobiotiques , INRA, BP 3, Toulouse , France.
authors.forename: F
authors.initials: F
authors.lastname: Anglade
authors.affiliation: b Unitat de Fisiologia, Departament de Bioquimica i Fisiologia, Facultat de Biologia , Barcelona , Spain.
authors.forename: C
authors.initials: C
authors.lastname: Rodriguez
authors.affiliation: b Unitat de Fisiologia, Departament de Bioquimica i Fisiologia, Facultat de Biologia , Barcelona , Spain.
authors.forename: M T
authors.initials: MT
authors.lastname: Mitjavila