Evidence for lipid peroxidation in atherosclerosis.

Lipid peroxidation may play a significant role in the initiation and progression of atherosclerotic plaque. Freshly harvested normal and atherosclerotic human aortic tissue, coronary arteries and explanted vein grafts were snap frozen at -70 degrees C. Folch reagent (chloroform-methanol 2:1, v/v) was used to extract lipids from the homogenates. These extracts were assayed for cholesterol, phospholipid and triglyceride content. Lipid peroxide complexes in vessels were measured fluorometrically. Atherosclerotic plaque from patients with aortic aneurysmal and occlusive disease and coronary artery disease contained significantly greater amounts of cholesterol (15.54 +/- 9.71 vs 3.39 +/- 1.14 mg/g tissue) than controls (p less than 0.01). Lipid peroxide fluorochromes were similarly elevated in all atherosclerotic tissue (4.159 +/- 1.065 vs 3.087 +/- 0.497 fluoro units/g tissue) compared to control (p less than 0.01) with significant elevations in saphenous vein grafts and occlusive aortic disease. Although lipid peroxidation and lipid accumulation occur in close association in atherosclerotic plaque, the role of lipid peroxides in the pathogenesis of atherosclerosis remains to be determined.