Effect of arterial proteoglycans on in vitro oxidation of LDL isolated from hypercholesterolemic patients
Barón, L.; López, F.
Acta Cientifica Venezolana 51(4): 211-222
2000
ISSN/ISBN: 0001-5504 PMID: 11460791 Document Number: 520166
The interaction of LDL with extracellular matrix proteoglycan apparently contribute to the accumulation of apo B-lipoproteins in atherogenesis. Retention of LDL by intima proteoglycans appears to increase the residence time needed for their structural, hydrolytic and oxidative modification. If the rate of LDL entry exceeds the tissue capacity to eliminate the modified products, this process may contribute to atherogenesis. In this study we explored whether alterations of LDL induced by human arterial CSPG alter the lipoprotein susceptibility to copper-catalyzed oxidation. Human LDL was complexed with human arterial CSPG and dissociated by raising the ionic strength. The CSPG-treated LDL was subjected to oxidation by micromolar amounts of copper. This treatment increased LDL susceptibility to oxidation 8 times, as indicated by formation rates of thiobarbituric acid-reacting substances (TBARS). Furthermore, the hypercholesterolemic patients show LDL with significantly higher affinity for arterial proteoglycans than LDL from controls.