[Quantitative study of endothelial defects in the aorta and carotid artery in experimental atherosclerosis].

The inner surface of the aorta and carotid artery in normal rabbits (group 1) and after 3 weeks (group 2), 6 weeks (group 3) and 8 months (group 4) of hypercholesterolemia was studied by scanning electron microscopy. In all the cases the area of de-endothelialized zones was equally small. Incidence of microdefects in the endothelium (argyrophilic cells, craters and stomata) increased in group 2, but decreased in group 3 and group 4 (outside the plaques). No typical endothelium with argyrophilic borders was observed on 39.2% of the plaque surface in group 4, though the cells were present. The data obtained show that vast zones of de-endothelialization do not precede the development of atherosclerotic plaques.