Effect of regenerated endothelium on collagen content in the injured artery

Collagen content and intimal thickness were measured in endothelialized and nonendothelialized zones of the aorta in rabbits for 30 days after a standard embolectomy balloon injury. A large increase in collagen content and intimal thickness were seen in the arterial wall covered by regenerating endothelium. In areas devoid of endothelial coverage, minimal intimal thickness occurred; no measurable increase in collagen content was measured. Interaction between arterial smooth muscle cells and regenerated endothelium appear to be necessary for collagen accumulation and intimal thickening after arterial injury and repair.