An increase in cholesterol ester content of the rat aorta by a high fat-high erucic acid diet

Rats of weaning age were feed for a period of 1 or 3 weeks either a low fat diet (laboratory stock diet) or a semi-synthetic diet containing 20% by weight of either corn oil (2/3 of the total fatty acids consisted of linoleic acid) or mustard seed oil (1/3 of the total fatty acids were comprised of erucic acid). Feeding of a diet rich in erucic acid for 1 week increased by twofold the cholesterol ester content of the aorta. However, the concentrations of unesterified cholesterol and individual phospholipids in the aorta were uninfluenced by hyperlipemia induced by this diet. Fatty acid analyses indicated that erucic (22:1) and eicosenoic (20:1) acids are found in the triglyceride and cholesterol esters of the aorta in the proportion similar to that found in the plasma triglyceride and cholesterol esters. Our results demonstrated further that a significantly greater quantity of 14C-labelled erucate than labelled palmitate, oleate or linoleate was incorporated into the cholesterol ester fraction of the control aorta. The incorporation rates of erucate and linoleate into phosphatidic acid were more rapid, while the rates of erucate into phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, phosphatidylinositol and lysophosphatidylcholine were significantly slower than those of other fatty acids.