Comparative studies of the physical state of the lipid phase of normal and hypercholesterolemic very low density lipoprotein

✍ Scribed by Victoria A. Ploplis; J.Kerry Thomas; Francis J. Castellino

• Publisher: Elsevier Science
• Year: 1979
• Tongue: English
• Weight: 658 KB
• Volume: 23
• Category: Article
• ISSN: 0009-3084
• DOI: 10.1016/0009-3084(79)90022-7

✦ Synopsis

Very low density lipoproteins (VLDL) were prepared from the serum of rabbits at various stages of hypercholestemlemia (95-1665 rng cholesterol/100 rnl of serum). The most notable chemical change in hypercholesterolemic (he) VLDL was the greatly increased content of cholesteryl esters and the greatly decreased content of trigiycerides, compared to normal (n) VLDL. Structurally, the lipid region of n VLDL possessed a much lower microviscosity than did he VLDL, when analyzed by fluorescence polarization and pyreue eximer methods. The microviscosiW of the redispersed n VLDL lipid extract was considerably greater than that observed in n VLDL; but less than that of he VLDL. Incorporation of pyrene into the lipid region of n VLDL and hc VLDL allowed assessment of various properties of the surface and hydrocarbon regions of these lipoproteins. Only slight differences were found in the pyrene monomer 3 : 1 fluorescence emission peak ratios, and in the rate constant for quenching of pyrene by O 2. However, the quenching rate constant of pyrene by I-and iodoheptane were different for each lipoprotein.