Hydroxyl radical attack of low density lipoprotein decreases its cellular catabolism in the absence of significant lipid peroxidation.
Low density lipoprotein (LDL) has been submitted to oxidative modification induced by gamma radiolysis of water under conditions generating either hydroxyl radical (OH.) alone, or a mixture of superoxide anion and OH.. Treatment of LDL with hydroxyl radical alone did not lead to significant lipid peroxidation as assessed by thiobarbituric acid reactive substances (TBARS) and hydroperoxide measurement and induced only very small change in the electrophoretic mobility of the particle. In contrast, superoxide and hydroxyl radical mixture induced a dose-dependent increase in lipid peroxidation, with a marked elevation of the negative net charge of the LDL. However, in both cases, a similar reduction of the uptake and degradation of modified LDL by the apo B/E receptor pathway of human fibroblasts was observed. This suggests that factors other than lipid peroxidation could play a role in LDL modification and influence their cellular metabolism.
Frey-Fressart
V
V
Laboratoire de Biochimie, Hôpital de la Salpétrière, Paris, France.
Bonnefont-Rousselot
D
D
Gardès-Albert
M
M
Delattre
J
J
Auclair
M
M
Mazière
C
C
Mazière
J C
JC
D002478:Cells, Cultured; D006801:Humans; D017665:Hydroxyl Radical / Q000737:chemistry*; D066298:In Vitro Techniques; D008054:Lipid Peroxides / Q000378:metabolism*; D008077:Lipoproteins, LDL / Q000737:chemistry / Q000378:metabolism*; D011940:Receptor Aggregation; D018110:Receptors, Lipoprotein / Q000378:metabolism; D013481:Superoxides / Q000737:chemistry
D008054:Lipid Peroxides; D008077:Lipoproteins, LDL; D018110:Receptors, Lipoprotein; C032531:apolipoprotein B,E receptor; D013481:Superoxides; D017665:Hydroxyl Radical