抄録
The morphologic changes of endothelial cells in the descending aorta were studied with scanning electron microscope (SEM) on hypovitamin C guinea pigs with or without cholesterol added diet for 4 weeks. During experimental period, serum cholesterol level and permeability into the aorta with labeled cholesterol were estimated. Four groups of experimental animals were fed on ordinary diet (group 1), on ascorbic acid deficient (group 2), on cholesterol added ordinary diet (group 3), on ascorbic acid deficient and cholesterol added diet (group 4). Endothelial changes observed with SEM were shown in Fig. 1. Flattering of the endothelial cells with indistinct cell border were observed in the early phase of hypovitamin C. Swollen endothelial cells with disarrangement were pild up and formed atherosclerotic lesion in the chronic hypovitamin C. Atherosclerotic changes were appeared in the early period of the experiment in group 3 and 4. Most characteristic feature in the group 4 was separation of endothelial border. Serum cholesterol of the group 3 and 4 were significantly elevated as compared that of the group 1 and 2 except the first week of feeding. Hypercholesterolemia indused with cholesterol feeding was enhanced with hypovitamin C (Fig. 2). The contents of 4-14c-cholesterol were measured 3rd, 7th and 14th day after intraperitoneal administration to the animals of the the second experimental week. The count in serum of the group 2 and 4 was appearently increased as compared with the other groups at 3rd and 7th day. Uptake of the aortic wall at the 3rd day of the group 4 was significant higher than the other groups. There was no difference of the uptake between the four groups at 7th and 14th day (Fig. 3). These findings suggest that injury of the endothelial cells induced with hypovitamin C is important one of initiaiing factors of atherosclerosis, and hypercholesterolemia and enhanced permeability of arterial wall acts as promoting factors of the atherogenesis.
