Although there have been numerous studies of atherosclerosis in the hypercholesterolemic rabbit, the initial cause for the development of the atherosclerotic plaque, as well as the identity and origin of its cellular elements, has been a subject of controversy.
In a recent issue of the Archives of Pathology, Friedman reports the first of a proposed series of studies concerned with these problems. In the first study,1 he has tried to scrutinize the experimental plaque by assessing it not only in its spatial dimensions but in its temporal dimensions as well. In addition, he has employed a thromboatherosclerotic plaque2 and a doubly ligated segment of the aorta as aids to understanding the source and directions of growth of arterial tissue elements.
Data from the spatial and temporal studies strongly suggest that the sequence of events involved in the pathogenesis of the atherosclerotic plaque may be quite different from that