The effect of polyunsaturated fatty acids on the n-3 and n-6 series on platelet aggregation and platelet and aortic fatty acid composition in rabbits.
Four groups of 6 New Zealand white rabbits were fed for 60 days on a commercial rabbit diet supplemented (60 g/kg) with 1 of 4 sources of fat: corn oil, linseed oil and fish oil, which respectively provided rich sources of linoleic acid (C18:2, n-6), alpha-linolenic acid (C18:3, n-3) and eicosapentaenoic acid (C20:5, n-3), and coconut oil, low in all polyunsaturated fatty acids (PUFA). Platelet-rich plasma was prepared and aggregation induced by ADP (final concentration 0.29-74.3 microM), collagen (2.5-20 micrograms/400 microliters, final concentration) and 2.5 U bovine thrombin, and recorded with a Peyton aggregometer. Platelet aggregation induced by both thrombin and collagen was significantly lower with either n-3 PUFA (fish or linseed oil) than with corn oil (n-6 PUFA) or the low PUFA coconut oil. ADP-induced platelet aggregation was significantly reduced only in animals fed fish-oil. Changes in platelet aggregation were accompanied by increased platelet lipid content of C20:5, n-3 and decreased content of C20:4, n-6, with little change in platelet total C20 fatty acids. Platelet levels of C20:5, n-3 were significantly increased with both the preformed C20:5, n-3 and its precursor C18:3, n-3 in the diet. However, aortic lipid accumulation of C20:5 only occurred with rabbits fed on fish oil. It was concluded that, for collagen and thrombin induced aggregation, C18:3, n-3 and C20:5, n-3 were equally antiaggregatory in rabbits. The implications of this in community nutrition programmes are discussed.
D000273:Adipose Tissue / Q000032:analysis; D000818:Animals; D001011:Aorta / Q000032:analysis*; D001792:Blood Platelets / Q000032:analysis*; D002784:Cholesterol / Q000097:blood; D003059:Cocos; D004041:Dietary Fats / Q000494:pharmacology; D005227:Fatty Acids / Q000032:analysis / Q000097:blood; D005231:Fatty Acids, Unsaturated / Q000008:administration & dosage / Q000145:classification / Q000494:pharmacology*; D005395:Fish Oils / Q000008:administration & dosage / Q000494:pharmacology; D008041:Linoleic Acids / Q000008:administration & dosage / Q000494:pharmacology; D008043:Linseed Oil / Q000008:administration & dosage / Q000494:pharmacology; D008099:Liver / Q000032:analysis; D010974:Platelet Aggregation / Q000187:drug effects*; D011817:Rabbits; D014280:Triglycerides / Q000097:blood
D004041:Dietary Fats; D005227:Fatty Acids; D005231:Fatty Acids, Unsaturated; D005395:Fish Oils; D008041:Linoleic Acids; D014280:Triglycerides; D008043:Linseed Oil; D002784:Cholesterol