Electron microscopic studies on cells isolated from aorta of newborn and adult rabbits

Cells from aortas of newborn and adult rabbits were liberated by digestion with trypsin and collagenase. More than 90% of them were viable at the end isolation. Isolated cells were used for electron microscopic examination. In the material obtained from aortas of newborn rabbits endothelial cells, fibroblasts and smooth muscle cells were present. In material from adult rabbits two kinds of endothelial cells, fibroblasts, several varieties of myocytes, fat-laden macrophages and typical foam cells were found. Various forms of myocytes seem to represent different functional stages or specialized kinds of these cells. The presence of fat laden macrophages and foam cells in the aortas of healthy adult rabbits may support the view that these cellular changes so far considered as typical of atherosclerosis are common and may be treated as an exponent of natural process of aging of vascular wall.