ABNORMALITIES IN PLATELETS AND VASCULAR ENDOTHELIAL-CELLS INDUCED BY GLYCATED LIPOPROTEINS

We studied the effects of glycated lipoproteins of low- and high-density (LDL and HDL) on platelets and vascular endothelial cells. After pretreatment for 5 minutes at 37-degrees-C, the thrombin-induced synthesis of thromboxane B2 in washed platelets was significantly increased by glycated LDL as compared with native LDL (198.9 +/- 16.2 vs 90.3 +/- 29.4 ng/10(9) platelets, n = 8, p < 0.01). Platelet aggregation was also increased by glycated LDL as compared with native LDL. After treatment with platelet-rich plasma for 5 hours at 37-degrees-C, these values were suppressed by native HDL vs the control (buffer), but not by glycated HDL. Abnormalities in the release of 6-keto prostaglandin F1-alpha and lactate dehydrogenase from vascular endothelial cells were also induced by glycated LDL and/or HDL. These observations suggest that abnormalities induced in platelets and vascular endothelial cells by glycated lipoproteins may play an important role in the development of atherosclerosis in patients with diabetes mellitus.