Henry Ford Hospital Medical Journal


Orhan N. Ulutin


In atherosclerosis, platelets appear to circulate in an activated state. Our findings are based on results obtained from 240 patients. These platelets demonstrated an increased degree of surface activation and an increased amount of aggregation. Platelet aggregation was also demonstrated by a heightened sensitivity to adrenalin and ADP. Greater than normal secretion of ADP, PF-4, platelet fibrinogen, and platelet antiplasmin was noted. Platelet antiplasmin was increased, whereas platelet antithrombin III was decreased. Membrane transport of glucose was found to be defective in atherosclerosis. There appears to be no alteration in the phospholipid distribution, although the amount of phospholipids increases. The order of secretion of phospholipids in ADP and collagen-induced secretion was found to differ in platelets from atherosclerotic patients when compared to normal platelet populations. The availablility of phospholipids rich In arachidonic acid was enhanced. Also, in atherosclerosis, we found a decrease in platelet c-AMP and an increase in c-GMP. The balance between TXA2 formation in platelets and PGI2 formation by the vessel wall is important in determining whether thrombus formation is encouraged or prevented.