Fatty Acid Incorporation into Cholesteryl Ester and Phospholipid by Arterial Subcellular Fractions of Swine

Abstract

Summary

Cholesterol esterifying and phospholipid synthesizing activities were measured with ¹⁴C-labeled palmitic, oleic, elaidic, and linoleic acid by subcellular fractions from the thoracic, abdominal aorta, and the coronary arteries of swine. Cholesterol esterification was most active in the microsomal fraction and considerable esterification was also found in the mitochondrial fraction. Oleic, palmitic, and linoleic acid were readily utilized for cholesteryl ester synthesis and elaidic acid was least utilized. Incorporation of fatty acids into phospholipid was very active in the aortic tissue. Most of the phospholipid synthesizing activity was found in the microsomal fraction, although considerable activity was present in the mitochondrial fraction. Among the fatty acids tested, linoleic acid was the most preferential substrate for phospholipid synthesis and the relative order of incorporation into phospholipid was linoleate > oleate > elaidate. In subcellular fractions from grossly normal aortic tissue, the utilization of fatty acid for phospholipid synthesis was many times greater than that for esterification to cholesterol. However, in cholesterol esterifying and phospholipid synthesizing activities, no significant differences were found in subcellular fractions between the thoracic, abdominal, and coronary arteries.

This work was supported by NIH Grant HL 15504-04 and the National Dairy Council. We would also like to acknowledge Mr. H. E. Moore for the use of his farm facilities.