Comparison of morphology of isolated cells obtained from aortas of normal and cholesterol fed rabbits.

Cells from aortas of healthy newborn and adult rabbits were liberated by digestion with trypsin and collagenase. In the same way were obtained free cells from the aortas of rabbits with far advanced experimental atherosclerosis. More than 90 p. 100 of the cells from all groups were viable. Isolated cells were used for electron microscopic examination. In material obtained from aortas of newborn rabbits, endothelial cells, fibroblasts and smooths muscle cells were present. In adult rabbits two kinds of endothelial cells, fibroblasts, several varieties of myocytes and foam cells were found. The bulk of aortic cells isolated from rabbits with experimental atherosclerosis consisted of endothelial cells and smooth myocytes. The cytoplasm of all myocytes contained lipid vacuoles. The lipid-loaded myocytes corresponded to the typical foam cells. Lipid content was relatively scanty in the endothelial cells. The presence of myocytes foam cells like in the aortas of healthy adult rabbits, identical as in material from experimental atherosclerosis, may support the view that these cellular changes so far considered as typical for atherosclerosis are common, and may be treated as an exponent of the natural process of aging of the vascular wall.