title: Alpha-tocopherol, an effective inhibitor of platelet adhesion.
abstract: Platelet adhesiveness was tested ex vivo in a group of six normal individuals receiving varying doses of alpha-tocopherol. Adhesion to glass slides coated with fibronectin, collagen, fibrinogen, or plasma proteins was studied by perfusing platelet-rich plasma through a flow chamber that allowed time- and space-resolved observations of platelet adhesion. Platelet adherence was measured in an area of parallel flow lines and low shear rate under standardized conditions before and after dietary supplementation with vitamin E at doses of 200 and 400 IU/d. Platelet adherence differed in magnitude depending on the adhesive surface. There was a distinct preference of platelets to adhere to sites that had been previously occupied. A remarkable decrease in platelet adherence was observed after vitamin E supplementation. The average decrease in adhesion after 2 weeks of 200 IU vitamin E was 75%. After 2 weeks of 400 IU vitamin E, platelet adhesion was reduced by 82%. The inhibitory activity of alpha-tocopherol was dose dependent and correlated well with the increase in alpha-tocopherol concentration in platelets after supplementation. Scanning electron microscopy revealed a striking decrease of pseudopodium formation in alpha-tocopherol-enriched platelets. Our results suggest that vitamin E may also be an effective antiadhesive agent in vivo.
authors.affiliation: Division of Hematology/Oncology, Brown University, Providence, RI.
authors.forename: J
authors.initials: J
authors.lastname: Jandak
authors.forename: M
authors.initials: M
authors.lastname: Steiner
authors.forename: P D
authors.initials: PD
authors.lastname: Richardson
mesh_terms: D001792:Blood Platelets / Q000032:analysis / Q000187:drug effects / Q000648:ultrastructure; D005260:Female; D005340:Fibrinogen; D005353:Fibronectins; D005898:Glass; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D010973:Platelet Adhesiveness / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage*; D015203:Reproducibility of Results; D012212:Rheology / Q000295:instrumentation; D013499:Surface Properties; D014810:Vitamin E / Q000008:administration & dosage*
chemical_list: D005353:Fibronectins; D010975:Platelet Aggregation Inhibitors; D014810:Vitamin E; D005340:Fibrinogen