Platelet-leukocyte interactions following arterial endothelial injury

Desquamation of canine arterial endothelium was induced by stripping the luminal surface of arteries with an inflated embolectomy catheter. The dogs were killed by intravascular perfusion fixation at intervals varying from 2 hours to 12 weeks after the procedure, and the arteries were studied by light microscopy, transmission electron microscopy, and scanning electron microscopy. A heretofore unreported, apparently specific interaction of aggregated platelets and polymorphonuclear leukocytes (PMNs) was observed on the luminal surface of the denuded arteries. This interaction was abolished by the administration of a single dose of aspirin prior to the application of the catheter. These observations suggest that this platelet--PMN interaction is distinctly different from the classic inflammatory reaction, and that it is an integral part of the arterial response to injury that may affect endothelial regeneration.