title: Alterations in cytoskeletal organization and tyrosine phosphorylation in platelet concentrates prepared by the buffy coat method.
abstract: BACKGROUND
  Numerous morphologic and biochemical changes occurring during platelet storage may result in the impairment of platelet function.
  
  
  METHODS
  The effect of preparation and storage conditions on platelet function was analyzed through evaluation of cytoskeletal organization and signaling mechanisms involved in the activation of platelets by thrombin. Samples of platelets prepared by the buffy coat method were obtained before and after the platelet concentrates were prepared during storage for 1, 3, and 5 days. Thrombin-induced aggregation was monitored, and changes in the organization of proteins in the cytoskeleton were analyzed by gel electrophoresis. For the analysis of tyrosine phosphorylation, proteins were transferred to nitrocellulose membranes and probed with a specific antibody.
  
  
  RESULTS
  The aggregation and the cytoskeletal organization induced by thrombin activation were markedly impaired immediately after preparation of platelet concentrates, although they normalized after the first 24 hours of storage and decreased progressively after 3 days of storage. Results in tyrosine phosphorylation paralleled those obtained with cytoskeletal organization, except for samples obtained immediately after processing to obtain platelet concentrates.
  
  
  CONCLUSIONS
  These data indirectly suggest that the stress induced by the preparation method has an activating effect on platelet function that may imply a delayed platelet response to further stimuli. This effect may result in a deficient redistribution of signaling molecules within platelets.
authors.affiliation: Hemotherapy and Hemostasis Service, Hospital Clínic, University of Barcelona, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Estebanell
authors.forename: M
authors.initials: M
authors.lastname: Díaz-Ricart
authors.forename: G
authors.initials: G
authors.lastname: Escolar
authors.forename: M
authors.initials: M
authors.lastname: Lozano
authors.forename: R
authors.initials: R
authors.lastname: Mazzara
authors.forename: A
authors.initials: A
authors.lastname: Ordinas
mesh_terms: D001792:Blood Platelets / Q000166:cytology; D001793:Blood Preservation; D003285:Contractile Proteins / Q000378:metabolism; D003599:Cytoskeleton / Q000648:ultrastructure; D004586:Electrophoresis; D006801:Humans; D010766:Phosphorylation / Q000187:drug effects; D015539:Platelet Activation; D010974:Platelet Aggregation; D013917:Thrombin / Q000494:pharmacology; D014443:Tyrosine / Q000378:metabolism
chemical_list: D003285:Contractile Proteins; D014443:Tyrosine; D013917:Thrombin