Platelets and Atherosclerosis — Experimental and Clinical Studies — (Abstract)

Abstract

Modern studies on atherogenesis have elucidated the important role platelets play not only in initiating thrombus formation, but in causing vascular injury which develops into atheromatous lesions. Our in vitro studies using animal models demonstrated that activated platelets release thromboxane A₂ and other vasoactive substances which induce edematous changes in the arterial wall. These changes result in acute plasmal infiltration into the arterial wall, including lipid particles. In vitro studies further indicate that activated platelets directly damage luminal endothelial cells. Cultured endothelial cells isolated from bovine aorta and preincubated with ³H-adenine were subjected to collagen-activated or sonicated human platelets, and resulted in damage to the cells as estimated by ³H-adenine release into the media. The release of ³H-adenine depended on their dosage and on the incubation time with activated platelets. The content of intracellular ATP and cyclic AMP decreased in endothelial cells treated with activated platelets.