Journal
ARTERIOSCLEROSIS THROMBOSIS AND VASCULAR BIOLOGY
Volume 23, Issue 10, Pages 1881-1888Publisher
LIPPINCOTT WILLIAMS & WILKINS
DOI: 10.1161/01.ATV.0000091338.93223.E8
Keywords
HDL subfractions; LDL oxidation; small, dense HDL; enzymatic activities; physicochemical properties
Categories
Ask authors/readers for more resources
Objectives - The relationship of the structural and functional heterogeneity of HDL particles to protection of LDL against oxidative stress is indeterminate. Methods and Results - HDL subfractions of defined physicochemical properties were isolated by density gradient ultracentrifugation from normolipidemic human serum (n = 8), and their capacity to protect LDL from oxidation was evaluated. Under mild oxidative stress induced by AAPH or Cu(II), HDL subfractions ( at equal cholesterol or protein concentration or equal particle number) significantly decreased LDL oxidation rate ( - 20% to - 85%) in the propagation phase (234 nm), which was prolonged by up to 82% with decreased maximal diene formation. Antioxidative activity of HDL subfractions increased with increment in density, as follows: HDL2b < HDL2a < HDL3a < HDL3b < HDL3c ( confirmed by thiobarbituric acid - reactive substance content and LDL electrophoretic mobility). Concordantly, antioxidative activity of small HDL prepared by FPLC was significantly higher ( + 56%) than that of large HDL. Antioxidative action of HDL subfractions was primarily associated with inactivation of LDL lipid hydroperoxides. The potent protective activity of small HDL could not be accounted for exclusively by enzymatic activities (PON1, platelet-activating factor acetylhydrolase, and lecithin-cholesterol acyltransferase). Conclusions - Small, dense HDL exhibit potent antioxidant activity, which may arise from synergy in inactivation of oxidized LDL lipids by enzymatic and nonenzymatic mechanisms, in part reflecting distinct intrinsic physicochemical properties.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available