Lipid Distribution and Metabolism in Two Areas of Aorta of Normal and Cholesterol-fed Rabbits

Summary

Lipid partition and phospholipid metabolism of the aortic arch and descending limb of aorta, plasma and liver were determined in groups of rabbits on a normal diet and 40 and 70 days on a cholesterol-supplemented diet. In all groups, the descending limb of aorta had significantly lower total lipid, primarily due to decreased neutral fat concentration, compared with the aortic arch. In normal rabbits the specific activity of phospholipid in the descending aorta was significantly greater than that of the aortic arch. However, this distinction in phospholipid synthesis between the two areas of aorta was not found in the groups of rabbits on the high-cholesterol diet. The radioactivity data indicated this was due to an increased rate of formation of phospholipid in the aortic arch of rabbits fed the cholesterol-supplemented diet, particularly those rabbits on the diet for 70 days, and probably was related to the development of atheromatous lesions in the arch only of these rabbits. The results were discussed in relation to the general problem of local factors in the arterial wall influencing the localization and subsequent development of atherosclerotic lesions.