Journal of Lipid Research (May 2002)
Density distribution of electronegative LDL in normolipemic and hyperlipemic subjects
Abstract
The density distribution of electronegative LDL [LDL(−)], a cytotoxic and inflammatory fraction of LDL present in plasma, was studied in 10 normolipemic (NL), 6 FH, and 11 hypertriglyceridemic (HTG) subjects. Six LDL subclasses of increased density (LDL1 to LDL6) were isolated by density-gradient ultracentrifugation (DGU). NL and FH subjects showed prevalence of light LDL, whereas HTG subjects showed prevalence of dense LDL. LDL(−) proportion was determined from total LDL or LDL-density subclasses by anion-exchange chromatography. LDL from FH patients had increased LDL(−) (35.1 ± 9.9%) compared with LDL from NL and HTG subjects (9.4 ± 2.3% and 12.3 ± 4.3%, respectively). Most LDL(−) was contained in dense subclasses in NL (LDL4–6, 67.7 ± 3.1%) whereas most of LDL(−) from FH patients were contained in light LDL subclasses (LDL1–3) (86.2 ± 1.6%). In these subjects, simvastatin therapy decreased LDL(−) to 28.2 ± 6.7% and 21.2 ± 5.6% at 3 and 6 months of treatment, respectively, due mainly to decreases in light LDL subclasses. In HTG subjects, half LDL(−) was contained in dense LDL subclasses (LDL4–6, 46.1 ± 2.0%). Non-denaturing acrylamide gradient gel electrophoresis concurred with DGU data, as LDL(−) from NL showed a single band of lower size than non-electronegative LDL [LDL(+)], whereas LDL(−) from FH and HTG presented bands of greater size than its respective LDL(+). These results reveal the existence of light and dense LDL(−), indicate that hyperlipemia could promote the formation of light LDL(−) and suggest that LDL(−) could have different origins.—Sánchez-Quesada, J. L., S. Benítez, C. Otal, M. Franco, F. Blanco-Vaca, and J. Ordóñez-Llanos. Density distribution of electronegative LDL in normolipemic and hyperlipemic subjects. J. Lipid Res. 2002. 43: 699–705.
