Electron Microscopic Exploration of Human Endothelium in Step-Serial Sections of Early and Advanced Atherosclerotic Lesions

Publisher Website
Google Scholar
Abstract
A transmission electron microscopic study of step-serial sections of numerous human early and advanced atherosclerotic lesions obtained under conditions preventing artificial endothelial loss was undertaken. It was found that (1) no endothelial denudation with platelet aggregation occurred over any early myoproliferative lesions, (2) endothelial denudation with platelet aggregation had developed only over the mostly necrotic caps of some advanced end-stage lesions, and (3) all stages of atherosclerosis showed endothelial changes that indicated increased permeability of the endothelium over plaques for plasma constituents, namely, opened interendothelial junctions and endothelial lipid inclusions. These results suggest that endothelial denudation and platelet aggregation is not an initiating event in human atherogenesis but something that happens late over the disintegrating surface of some end-stage lesions as a prelude to supra-plaque thrombosis--in agreement with our light microscopic findings of 25 years ago that thrombosis in human atherosclerotic arteries is usually triggered by a breakdown of the mostly necrotic caps of advanced plaques.