DIETARY N-3 POLYUNSATURATED FATTY-ACIDS MODIFY SYRIAN-HAMSTER PLATELET AND MACROPHAGE PHOSPHOLIPID FATTY ACYL COMPOSITION AND EICOSANOID SYNTHESIS - A CONTROLLED-STUDY

The aim of this study was to determine the effects of varying intakes of dietary n - 3 polyunsaturated fatty acids (PUFA) on the fatty acyl composition and arachidonic acid metabolite synthesis of platelets and macrophages in Syrian hamsters consuming diets that were strictly con trolled for n - 6 PUFA content. Animals consumed highly controlled die ts which were not supplemented with n - 3 PUFA (control) or supplement ed with 0.4%, 0.8% or 2% (w/w) n - 3 fatty acids. The content of n - 3 PUFA in cellular phospholipids increased progressively with the intak e of n - 3 PUFA, while n - 6 PUFA, including arachidonic acid, decreas ed despite the constant intake of 18:2(n - 6); this latter effect was more substantial in macrophages than in platelets. The synthesis by st imulated macrophages of prostaglandin E(2), 6-keto-prostaglandin F-1 a lpha thromboxane B-2 and 11- and 15-hydroxyeicosatetraenoic acids decr eased with the intake of 0.8% n - 3 PUFA to 30-50% of the control valu es. Little effect of diets on platelet aggregation and eicosanoid synt hesis was observed reflecting the limited effect on platelet arachidon ic acid content. The synthesis of 12-hydroxyeicosapentaenoic acid by s timulated platelets increased with n - 3 PUFA consumption in a dose-de pendent fashion. Circulating triacylglycerols and HDL-cholesterol were decreased only in animals consuming 2% n - 3 PUFA. The strict control of n - 6 PUFA intake allows the determination of the effects of n - 3 PUFA intake on the measured parameters without confounding effects