Docosahexanoic acid and docosapentanoic acid incorporation into human platelets after 24 and 72 hours: Inhibitory effects on platelet reactivity

Short-term in vitro platelet membrane lipid enrichment studies and feeding trials of human subjects with eicosapentanoic acid (EPA) and docosahexanoic acid (DHA) have shown a decreased reactivity in the platelet response to c ollagen. In this study, exogenous albumin-bound n-3 polyunsaturated fatty a cids (PUFAs), namely EPA, DHA and docosapentanoic acid (DPA) were added to platelet suspensions and maintained at 22 degrees C for 24 and 72 hours. Su bsequently, the aggregation response to agonist stimulation and the morphol ogical appearance of the platelets were evaluated, A significant enrichment of platelet phospholipids (PL) in n-3 fatty acids occurred upon incubation with n-3 PUFAs in vitro, which was accompanied by a decrease in the aggreg ation response to collagen and preservation of platelet morphology compared with non-supplemented control platelet preparations. The inhibitory effect of the n-3 PUFAs appeared to be surface mediated in the case of DHA and DP A because the platelet response to agonist returned when the fatty acids we re removed by washing. The platelet aggregation response after storage at 2 2 degrees C was also evaluated in platelet suspensions collected from healt hy individuals before and after 42 days of dietary supplementation with sea l oil, rich in DPA and DHA, Unlike the in vitro supplementation, in vivo mo dification and enrichment of platelet PLs by ingestion of seal oil did not appear to improve platelet function during storage relative to the placebo group.