Abstract
Electron microscopic observation was carried out on the abdominal aorta and coronary artery of rats fed an atherogenic diet (containing 3% cholesterol, 1% cholic acid, 0.3% thiouracil and 21% hydrogenated fat) for 28 days combined with oral administration of vitamin D2 (320000 IU/kg/day) for the initial 4 days. Although the changes found in these two different types of artery were essentially similar to each other and characterized by the presence of lipid containing foam cells especially in the intima, some differences were detected between these arteries. Namely, deposition of fine fibrillar and granular materials, appearance of extracellular lipid crystals and increase in number of modified smooth muscle cells were apparent in the coronary artery, while increase in number of lipid-laden smooth muscle cells was conspicuous in the abdominal aorta. In addition, the present study demonstrated the possibility of transformation of both the smooth muscle cell and monocyte into foam cell.
