Venous response to endothelial denudation.

This paper examines the responses of various rat and rabbit veins to endothelial injury and compares them with endothelial injury in the carotid artery of the same species. Areas of endothelial injury of different sizes were produced by air-drying, enzymatic digestion with trypsin, or rubbing the endothelial surface with a nylon filament attached to the end of a catheter. Two weeks after an extensive area of endothelium had been denuded the artery contained a fibromuscular intimal thickening covered by regenerated endothelium. Experimental endothelial denudation of a similar size and produced by the same methods in a vein elicited a comparable intimal thickening, although more limited, than that in the carotid artery. When the size of the denuded area was large, extensive platelet microthrombi were formed that often caused total thrombotic occlusion in the vein. However, if the denuded area was small, the endothelium regenerated rapidly and no intimal thickening occurred.