Lipoproteins in atherosclerotic lesions. Localization by immunofluorescence of apo-low density lipoproteins in human atherosclerotic arteries from normal and hyperlipoproteinemics.

Using immunofluorescence techniques, apoLDL, the major protein component of human plasma low and very low density lipoproteins was localized in athersclerotic lesions from the aorta, coronary, and carotid arteries in human normolipoproteinemic, type II, and type IV hyperlipoproteinemics. Although no apoLDL was detected in uninvolved arteries, atheromas from advanced lesions as well as certain collagen and elastic fibers from both fatty streaks and advanced lesions were positive for apoLDL. This localization pattern was the same in each lipemic group, except for the presence of apoLDL in some intimal cells from type II cases. However, extensiveness of apoLDL localization was greatest in the type II group, but equal in the normolipemic and type II group. This may be explained by the high concentration gradient between plasma and tissue for apoLDL in the type II group.