CHEMICAL CHARACTERIZATION OF PEROXIDIZED LOW-DENSITY-LIPOPROTEIN IN PLASMA AND AORTIC ATHEROMA

Hydroperoxidized cholesteryl linoleate (HPO-CL, spot X(1)) was produce d by peroxidation of normal LDL isolated from plasma elf healthy perso ns. Spot X(1) stained on thin-layer chromatography plate (silica 60) b etween triglycerides and free fatty acids. The solvent mixture used co nsisted of petroleum ether 75, ethyl ether 25, and acetic acid 1. Spot X(1) of plasma from healthy subjects stained slightly. It was also id entified in plasma LDL of patients with atherosclerotic diseases, and in total lipids extracted from aortic atheroma obtained al autopsy. Wh ereas spot X(1) obtained from plasma LDL of patients with atherosclero tic diseases consisted of HPO-CL, spot X(1) obtained from aortic ather oma was reduced HPO-CL (hydroxide CL). Spot Xi of aortic atheroma did not react to p-methoxydiphenylpyrenylphosphine (MP(3)) - an agent whic h shows only positive reaction to hydroperoxide chemical structures - although spot X(1) of plasma LDL from atherosclerotic diseases reacted positively to MP(3). Moreover, spot X(1) obtained from aortic atherom a showed the same Rf value as that of the reduced HPO-CL, The IR profi le of spot X(1) obtained from aortic atheroma was similar to that of h ydroxide CL, although the IR profile of HPO-CL was similar to that obt ained from plasma LDL of atherosclerotic patients, In addition, HPO-CL was not recognized in the LDL fraction with clathrin-coated pits from aortic atheroma.