Comparative study of eicosapentaenoic acid metabolism by human platelets in vivo and in vitro
During long-term dietary n-3 fatty acid supplementation, eicosapentaenoic acid (EPA) is not incorporated into phosphatidylinositol or -serine of human platelets in vivo and is not detectable in phosphatidic acid upon stimulation with thrombin. However, EPA is released from platelet phospholipids and metabolized to thromboxane B3 (TXB3). In contrast, in vitro, platelets incorporate (/sup 14/C)EPA into phosphatidylinositol, whether they contain endogenous EPA in their cellular lipids or not. Following platelet stimulation, (/sup 14/C)EPA appears in phosphatidic acid, as free fatty acid, and is transformed to TXB3. The authors conclude that the fatty acid compositions of platelet phospholipid subclasses are regulated with a high degree of specificity in vivo. Qualitative differences exist between in vivo and in vitro uptake of EPA into platelet phospholipid subclasses. After in vivo incorporation, EPA is released by action of a phospholipase A2.
- Research Organization:
- Universitaet Muenchen, Germany, F.R.
- OSTI ID:
- 5151058
- Journal Information:
- J. Lipid Res.; (United States), Vol. 4
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
CARBOXYLIC ACIDS
METABOLISM
BIOCHEMICAL REACTION KINETICS
BLOOD PLATELETS
CARBON 14 COMPOUNDS
COMPARATIVE EVALUATIONS
IN VITRO
IN VIVO
PHOSPHOLIPIDS
TRACER TECHNIQUES
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BODY FLUIDS
ESTERS
ISOTOPE APPLICATIONS
KINETICS
LABELLED COMPOUNDS
LIPIDS
MATERIALS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
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550501* - Metabolism- Tracer Techniques