Reduced plasma high-density lipoprotein and increased platelet activity in arterial versus venous blood.

Plasma lipid and lipoprotein pattern and platelet activity were studied in blood samples derived from veins and arteries of 10 healthy male subjects. A significant reduction in plasma high-density lipoprotein (HDL) cholesterol, triglyceride and protein levels, as well as in plasma apolipoprotein A-I, was found when lipoproteins were derived from arterial blood in comparison to venous blood. All other lipoproteins were not significantly changed. Platelet activity measured as plasma beta-thromboglobulin levels and as collagen-induced platelet aggregation and 14C-serotonin release in platelet-rich plasma was markedly elevated when platelets were derived from arterial blood. Since reduced plasma HDL concentration and platelet activation are known risk factors for atherosclerosis, our study may suggest a further explanation for the presence of atherosclerotic lesions in arteries but not in veins.