Lipids of Human Platelets and Their Action on the Blood Coagulation Process.

M ANY WORKERS have shown that phospholipids accelerate in vitro coagulation of blood. Recent advances in the methods of total lipid extraction13 and in chromatographic3’4 and countercurrent distribution5 technics for the separation of lipid classes have intensified interest in the identification of the specific lipid moieties of platelets which accelerate the blood coagulation process. In the past, investigations of platelet lipids have been limited to studies on the physiologic activity of the platelet phospholipid entities-namely phosphatidylethanolamine ( PE ) #{176} and phosphatidylserine ( PS ) ;641 j contrast, no information is available on the physiologic effects of isolated neutral lipid fractions on the blood coagulation process. The object of the present study was to fractionate total lipid extracts of human platelets into various lipid classes by chromatography and countercurrent distribution, and to determine the effects of these isolated lipid classes, both individually and in combination with one another, on the blood coagulation process.