[Oxidation of lipoproteins and mechanism of action of antioxidants : contribution of gamma radiolysis].
Water gamma radiolysis leads to a selective and quantitative production of radical species, which allows the study of the one-electron oxidation or reduction of several biological systems, especially lipoproteins. Well defined quantities of*OH, O2*-/HO2* or RO2*. free radicals can thus be specifically produced by radiolysis of water or of ethanol. Such radical species can initiate one-electron oxidation reactions on compounds dissolved in water or in ethanol. Given the oxidative hypothesis of atherosclerosis, it is classically admitted that the oxidation of low density lipoproteins (LDL) but also of high density lipoproteins (HDL) is involved in the development of the atherosclerotic process. Nevertheless, the initiation mechanisms of this oxidation are still poorly defined. Therefore, gamma radiolysis is a method of choice for the study of the mechanisms of oxidation of LDL and HDL by oxygenated free radicals (*OH, O2*-, HO2*, RO2*). Gamma radiolysis allows to obtain oxidized lipoproteins with a very well defined oxidation status, and is a less drastic method than other currently used oxidation procedures such as those using for example copper ions. Finally, gamma radiolysis is also especially appropriate to study the mechanisms of action of antioxidant molecules, either in pure solutions or as inhibitors of lipid peroxidation in lipoproteins in vitro.
Bonnefont-Rousselot
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Laboratoire de biochimie, Hôpital de la Salpêtrière, 47, boulevard de l'Hôpital, 75651 Paris cedex 13, France.
D005609:Free Radicals; D005720:Gamma Rays; D006801:Humans; D015227:Lipid Peroxidation; D008075:Lipoproteins, HDL / Q000528:radiation effects*; D008077:Lipoproteins, LDL / Q000528:radiation effects*
D005609:Free Radicals; D008075:Lipoproteins, HDL; D008077:Lipoproteins, LDL
Oxydation des lipoprotéines et méchanisme d'action des anti-oxydants: apport de la radiolyse gamma.