Peroxidation of low density lipoproteins by several oxygen free radicals generated by gamma radiolysis
- 1. Hopital de la Salpetriere, 75 - Paris (France)
- 2. Paris-5 Univ., 75 (France)
Description
In vitro studies of lipid peroxidation of human low density lipoproteins (LDL 1.5 g/l) in aqueous solutions buffered at pH 7 have been investigated using steady state radiolysis to produce selectively oxygen-centred free radicals OH· or O2-·. The effects of increasing doses (up to 800 Gy, dose rate = 3.4.10-2 Gy/s) have been followed by measuring: the formation of malondialdehyde (MDA), the disappearance of vitamin E, and the evolution of the electrophoretic mobility on agarose gel. In each case studied, vitamin E was consumed in a dose-dependent manner before the onset of lipid peroxidation, in agreement with the antioxidant properties of this vitamin. In the absence of oxygen, OH· radicals produced only very limited peroxidation (G(MDA) ≅ 10-8 mol/J), whereas in the presence of oxygen the initial G value of MDA was enhanced by a factor of 10 (G(MDA) ≅ 10-7 mol/J). Superoxide anions induced, as expected, little lipid peroxidation. The electrophoretic mobility increased with the degree of lipid peroxidation measured by the formation of MDA
Abstract (French)
La lipidoperoxydation des LDL (1,5 g/l), en solution aqueuse tamponnee a pH 7, a ete etudiee par radiolyse gamma, in vitro, en selectionnant les radicaux libres oxygenes OH· ou O2-·. L'action de doses d'irradiation croissantes (de 0 a 800 Gy, debit de dose = 3,4.10-2 Gy/s) a ete suivie en mesurant: la formation de dialdehyde malonique (MDA), la disparition de la vitamine E et l'evolution de la mobilite electrophoretique sur gel d'agarose. Dans tous les cas etudies, la disparition de la vitamine E precede toujours l'apparition du MDA, en accord avec le role protecteur que joue la vitamine E vis-a-vis des chaines de peroxydation lipidique. En l'absence d'oxygene, les radicaux OH· sont de faibles initiateurs de la peroxydation lipidique (G(MDA) ≅ 10-8 mol/J), alors qu'en presence d'oxygene le rendement initial d'apparition du MDA est multiplie par 10 (G(MDA) ≅ 10-7 mol/J). Quant aux radicaux O2-·, ils n'initient, comme prevu, qu'une tres faible peroxydation lipidique. La mobilite electrophoretique croit de maniere concomitante avec la formation de MDAAdditional details
Additional titles
- Original title (French)
- Peroxydation des lipoproteines de basse densite (LDL) par divers radicaux libres oxygenes produits par radiolyse gamma
Publishing Information
- Journal Title
- Journal de Chimie Physique et de Physico-Chimie Biologique
- Journal Volume
- 88
- Journal Issue
- 6
- Series
- J. Chim. Phys. Phys.-Chim. Biol.
- Journal Page Range
- 913-925
- ISSN
- 0021-7689
- CODEN
- JCPBA
Conference
- Title
- 5. Meeting on Radiation Chemistry.
- Original Conference Title
- 5. Journees d'Etudes sur la Chimie sous Rayonnement
- Dates
- 1-6 Jul 1990.
- Place
- Sherbrooke, PQ (Canada).
INIS
- Country of Publication
- France
- Country of Input or Organization
- France
- INIS RN
- 23033962
- Subject category
- S38: RADIATION CHEMISTRY, RADIOCHEMISTRY AND NUCLEAR CHEMISTRY;
- Resource subtype / Literary indicator
- Conference
- Descriptors DEI
- AQUEOUS SOLUTIONS; GAMMA RADIATION; HYDROXYL RADICALS; LIPOPROTEINS; OXIDATION; PEROXY RADICALS; PH VALUE; RADIATION DOSES; RADIOLYSIS
- Descriptors DEC
- CHEMICAL RADIATION EFFECTS; CHEMICAL REACTIONS; DECOMPOSITION; DISPERSIONS; ELECTROMAGNETIC RADIATION; HOMOGENEOUS MIXTURES; IONIZING RADIATIONS; LIPIDS; MIXTURES; ORGANIC COMPOUNDS; PROTEINS; RADIATION EFFECTS; RADIATIONS; RADICALS; SOLUTIONS