title: Assessment of omega-fatty-acid-supplemented human platelets for potential improvement in long-term storage.
abstract: Uptake of omega (omega)-3 fatty acids can influence membrane stability and cell mobility. We investigated the effects of omega-3 and -6 fatty acids on the hemostatic efficacy of human platelets using an in vivo rabbit bleeding model. In vitro assays such as platelet aggregation, vWF bead-mediated ATP release and platelet adhesion to beads (measured by the residual platelet count [RPC] [free platelet count after reacting with the beads]/[baseline platelet count]x 100=%RPC; a high %RPC indicates reduced platelet function) were conducted on platelets treated with 1% fish oil (omega-3); 2% fish oil emulsion or 1% soy oil (omega-6). Oil treatment of platelets reduced the vWF bead-induced ATP release insignificantly. Addition of omega-3 agents reduced physical reactivity (%RPC) with the vWF beads by a factor of 1.2 (oil) and 1.9 (emulsion). The omega-6 oil enhanced reactivity by a factor of 1.7. After washing to remove excess reagent, platelet resuspension was most efficient with the omega-3 emulsion. Platelet function was higher with the omega-3-treated platelets (%RPC=52.3%, omega-3 oil; 63.3%, omega-3 emulsion vs. 85%, omega-6 oil; 82% untreated platelets). Ethyl-palmitate-treated thrombocytopenic rabbits were infused with human platelets. Survival times of the treated platelets, as monitored by flow cytometry (6.2-8.2 h) were comparable to untreated platelets (8.6 h). In the rabbit kidney injury model, blood loss after infusion of the treated platelets was similar to that of saline-infused rabbits (75.3+/-3.4 g). However, platelets washed prior to infusion reduced blood loss to a value comparable to that of fresh platelets (48.3+/-5 g). Furthermore, the presence of the infused platelets at the injury site was clearly visualized using FITC-tagged anti CD42a antibody. Thus, the omega-3-based agents protect the platelets from damage during the washing procedure as demonstrated in vitro by improved platelet resuspension, low %RPC, high stimulus-responsive ATP secretion and a reduction in blood loss in vivo.
authors.affiliation: Department of Blood Research, Walter Reed Army Institute of Research, Silver Spring, MD 20910-7500, USA. krishnac@nhlbi.nih.gov
authors.forename: Chitra
authors.initials: C
authors.lastname: Krishnamurti
authors.forename: Michael W
authors.initials: MW
authors.lastname: Stewart
authors.forename: Mary A
authors.initials: MA
authors.lastname: Cutting
authors.forename: Stephen W
authors.initials: SW
authors.lastname: Rothwell
mesh_terms: D000818:Animals; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism*; D001793:Blood Preservation / Q000379:methods*; D002465:Cell Movement; D002470:Cell Survival / Q000187:drug effects; D019587:Dietary Supplements; D004195:Disease Models, Animal; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage / Q000493:pharmacokinetics* / Q000494:pharmacology; D006470:Hemorrhage / Q000628:therapy; D006487:Hemostasis / Q000187:drug effects; D006801:Humans; D008297:Male; D015539:Platelet Activation / Q000187:drug effects; D010979:Platelet Function Tests; D017713:Platelet Transfusion / Q000379:methods / Q000592:standards; D011817:Rabbits; D014183:Transplantation, Heterologous
chemical_list: D015525:Fatty Acids, Omega-3