Biosynthesis of acylglycerol fatty acids in dog arteries.

The incorporation of (2-14C) acetate into the diacylglycerol and triacylglycerol fatty acids of three aortic layers and of the coronary arteries of the dog was investigated. In all tissues of the health animals, 50-60% of the label was found in the fatty acids greater than C16. This percentage was significantly higher in the diacylglycerols of the aortic media than in the adjacent layers or in the triacylglycerols of the media preparation. Under the influence of an atherogenic diet rich in cholesterol, incorporation of the label into the long chain fatty acids of the acylglycerols was markedly elevated in the aortic media and in the coronary artery. These results are interpreted in terms of metabolic alterations due to hypoxia in the normal aortic media and under hypercholesterolemic conditions. An active metabolic role of the diacylglycerols without net accumulation in the aortic media is discussed. In addition, the present data lend support to recent results on the coronary arteries and their susceptibility to atherogenesis.