title: Inhibitory effect of vitamin E (alpha-tocopherol) on spontaneous platelet aggregation in whole blood.
abstract: Vitamin E (D-alpha-tocopherol) inhibited spontaneous human platelet aggregation in whole blood in the 20-200 micrograms/ml range. When alpha-tocopherol (20 micrograms/ml) and aspirin (0.5 mM), or alpha-tocopherol and the mixture of phosphocreatine (1.5 mM) and creatine phosphokinase (50 U/ml) (CP/CPK) were added to this reaction system, a synergic inhibitory effect on aggregation was observed. On the other hand, when both alpha-tocopherol and the specific inhibitor of platelet activating factor (CV-3988; 0.38 mM) were added to this system, the inhibition was the same as that caused by the addition of CV-3988 alone, suggesting there was no synergism, i.e., that the effect of alpha-tocopherol is related to the inhibition of platelet activating factor (PAF)-induced platelet aggregation in whole blood. However, alpha-tocopherol (20 or 50 micrograms/ml) did not inhibit PAF (10 nM) induced platelet aggregation in platelet rich plasma (PRP). These results suggest that the inhibition of platelet aggregation in whole blood by alpha-tocopherol is due to the inhibition of PAF synthesis, and is unrelated to adenosine diphosphate (ADP) or thromboxane A2.
authors.affiliation: Department of Internal Medicine, Hyogo College of Medicine, Japan.
authors.forename: E
authors.initials: E
authors.lastname: Kakishita
authors.forename: A
authors.initials: A
authors.lastname: Suehiro
authors.forename: Y
authors.initials: Y
authors.lastname: Oura
authors.forename: K
authors.initials: K
authors.lastname: Nagai
mesh_terms: D000244:Adenosine Diphosphate / Q000037:antagonists & inhibitors; D000328:Adult; D001241:Aspirin / Q000494:pharmacology; D003402:Creatine Kinase / Q000494:pharmacology; D004357:Drug Synergism; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D010725:Phosphocreatine / Q000494:pharmacology; D010742:Phospholipid Ethers / Q000494:pharmacology; D010972:Platelet Activating Factor / Q000037:antagonists & inhibitors; D010975:Platelet Aggregation Inhibitors; D014700:Verapamil / Q000494:pharmacology; D014810:Vitamin E / Q000494:pharmacology*
chemical_list: D010742:Phospholipid Ethers; D010972:Platelet Activating Factor; D010975:Platelet Aggregation Inhibitors; D010725:Phosphocreatine; D014810:Vitamin E; D000244:Adenosine Diphosphate; C037913:CV 3988; D014700:Verapamil; D003402:Creatine Kinase; D001241:Aspirin