Endothelial regeneration. III. Time course of intimal changes after small defined injury to rat aortic endothelium.

The response to injury of the intima of the rat aorta was studied using a nylon monofilament to produce small, defined areas of endothelial denudation. A row of endothelial cells, three to five cells wide, was removed by pulling the tip of the filament along the length of the aorta. Platelet adhered to the exposed subendothelium. After 48 hours, this wound was covered by replicating endothelial cells which were densely packed together. This increased density remained over the site of injury for at least 4 weeks. A circular injury denuded a zone one to two endothelial cells wide. This wound was repopulated by endothelial cells within 8 hours without cell replication. No intimal thickening occurred in the vessels after either injury.