Incorporation of [1− 14C]-Linoleic acid into lipids of human umbilical arteries

Abstract

Summary [1− 14 C]-Linoleic acid introduced into the lumen of human umbilical arteries was shown to be incorporated into neutral lipids and phospholipids No loss of the enzymic activity was observed 2–4hours post partum if the cord has been kept at 0° C. The arterial segments differed markedly from the connective tissue of the cord in the extent of incorporation and distribution of the fatty acid between neutral lipids and phospholipids. The rate of fatty acid esterification was proportional to the dry weight of the incubated segments and to the time of incubation. It was not dependent on the presence of oxygen and glucose in the incubation medium. Two-thirds of the labeled fatty acid were found in the neutral lipid fraction of which more than 90% were recovered in the triglycerides. One-third was found in the phospholipids of which the major labeled component was lecithin. Evidence has been presented that α-glycerophosphate is the major fatty acid acceptor in the lipid-synthesizing system of the human umbilical artery.