+ Site Statistics
+ Search Articles
+ Subscribe to Site Feeds
EurekaMag Most Shared ContentMost Shared
EurekaMag PDF Full Text ContentPDF Full Text
+ PDF Full Text
Request PDF Full TextRequest PDF Full Text
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter
Follow on Google+Follow on Google+
Follow on LinkedInFollow on LinkedIn

+ Translate

Oxidation of low density lipoprotein by iron or copper at acidic pH

Journal of Lipid Research 36(12): 2504-2512

Oxidation of low density lipoprotein by iron or copper at acidic pH

Oxidized low density lipoprotein (LDL) may play a significant role in atherosclerosis. We have investigated the effect of pH on the oxidation of LDL by iron or copper. When LDL was oxidized by iron in the presence of cysteine in either Hanks' balanced salt solution (HBSS) or Ham's F-10 medium, an acidic pH greatly decreased the lag period and increased the rate of formation of hydroperoxides and thiobarbituric acid-reactive substances (TBARS), and increased its uptake by macrophages. There was a dose-dependent increase of LDL oxidation at acidic pH in the presence of increasing concentrations of cysteine. When LDL was oxidized by copper in HBSS, an acidic pH increased the lag phase before the rapid formation of conjugated dienes, hydroperoxides, and TBARS, but increased its uptake by macro. phages. Similar results were obtained using Ham's F-10 medium. Cysteine (100 micromolar) inhibited the modification of LDL by copper in HBSS at both pH 7.4 and 5.5. As atherosclerotic lesions may be acidic, these observations may help to explain why LDL oxidation occurs locally at these sites.

Accession: 002914080

PMID: 8847477

Related references

Iron released from transferrin at acidic pH can catalyse the oxidation of low density lipoprotein. FEBS Letters 352(1): 15-18, 1994

Oxidation of low-density lipoprotein by copper and iron in phosphate buffer. Biochimica et Biophysica Acta 1084(2): 198-201, 1991

Comparative effects of copper, iron, vanadium and titanium on low density lipoprotein oxidation in vitro. Iranian Biomedical Journal 11(2): 113-118, 2007

Improved measurement of low-density-lipoprotein susceptibility to copper-induced oxidation: application of a short procedure for isolating low-density lipoprotein. Clinical Chemistry 38(10): 2066-2072, 1992

A rapid and simple method for measuring the susceptibility of low-density-lipoprotein and very-low-density-lipoprotein to copper-catalyzed oxidation. Clinica Chimica Acta. 227(1-2): 159-173, 1994

Physiological thiol compounds exert pro- and anti-oxidant effects respectively, on iron- and copper-dependent oxidation of human low-density lipoprotein. Biochimica Et Biophysica Acta. 1345(2): 215-221, 1997

Mechanism of high-density lipoprotein subfractions inhibiting copper-catalyzed oxidation of low-density lipoprotein. Clinical Biochemistry 31(7): 537-543, 1998

Use of a nonexchangeable probe to monitor particle-specific oxidation kinetics in mixed systems Evidence that high density lipoprotein inhibits low density lipoprotein oxidation by FeCl-3 without simultaneous oxidation. Circulation 90(4 PART 2): I136, 1994

A role for apolipoprotein(a) in protection of the low-density lipoprotein component of lipoprotein(a) from copper-mediated oxidation. Archives of Biochemistry and Biophysics 412(2): 186-195, 2003

Copper and copper-nicotinic acid complexes mediated oxidation of high density lipoprotein. Basic Life Sciences 49: 381-385, 1988