Effect of endothelial cell denudation on fatty acid metabolism by rabbit aorta

The potential regulatory role of vascular endothelial cells in fatty acid uptake and metabolism by arterial tissue was studied in vitro using aortic segments from New Zealand White rabbits. Endothelium was left intact or was removed either by scraping with forceps or by rubbing with a cotton swab. Aortic segments were incubated with [14C]oleate or [14C]arachidonate, and oxidation and esterification were measured. Endothelial cell denudation by forceps or cotton swab caused a decrease in oxidation of both oleic and arachidonic acid. Esterification of oleic and arachidonic acid into phospholipid was also significantly reduced by removing the endothelium; the percent reduction was less when endothelium was removed by cotton swab than it was by forceps. Incorporation into phospholipid was reduced by cotton swab treatment, but incorporation into triglyceride was unaffected. Forceps treatment reduced oleic acid esterification into both triglyceride and phospholipid. The studies suggest that arterial endothelium has a role in fatty acid oxidation and esterification and that fatty acid utilization may be a useful metabolic index of vascular injury.