Platelet Activity in Pathogenesis of Atherosclerosis

To the Editor: Ross and Glomset are to be congratulated for their extensive review emphasizing “the importance of smooth-muscle cell proliferation as a key event” in the pathogenesis of atherosclerosis.¹Since they have kindly cited the work of our laboratory, we should like to report the most recent fruits of our investigations. The authors argue that platelet-derived serum factors are responsible for stimulating intimal cell proliferation after endothelial injury. Although we have confirmed the importance of platelets in the “injury-arteriosclerosis” schema, we have demonstrated that their role is limited. Whereas platelet factors are capable of initiating smooth-muscle cell mitosis. . .