EFFECTS OF PURIFIED LIPID FRACTIONS FROM HUMAN PLATELETS ON THE BLOOD COAGULATION PROCESS,

摘要

The purpose of the study was to purify and identify the various lipid components in human thrombocytes and to study their effects on the blood coagulation process. Lipid extracts of human platelets yielded a non-lipid fraction with anticoagulant activity. This activity is distinct from the acid mucopolysaccharides known to be present in whole platelets. Tests for vitamins A, D, E,and K, 17-ketosteroids,and 20-alpha-ketols in platelet lipid extracts were negative. The neutral lipids as well as purified lecithin, sphingomyelin,and inositol phosphatide fractions of human platelets were void of thromboplastic activity when tested by themselves or in combination with one another. Both phosphatidylserine and phosphatidylethanolamine exhibited thromboplastic activity. Phosphatidylserine at high concentrations showed anticoagulant activity. A combination of phosphatidylethanolamine and phosphatidylserine showed synergistic thromboplastic activity. When combined with lecithin,the thromboplastic activity of phosphatidylserine was greatly enhanced. Human platelets contain a variety of neutral lipids and phospholipids. The phospholipids were separated into five major fractions. The thromboplastic and anticoagulant activity of the lipid fractions were characterized. (Author)