THE RELATIONSHIP BETWEEN ALTERED MEMBRANE-COMPOSITION, EICOSANOIDS AND TNF-INDUCED IL1 AND IL6 PRODUCTION IN MACROPHAGES OF RATS FED FATS OF DIFFERENT UNSATURATED FATTY-ACID COMPOSITION

The study investigated the changes in individual molecular species in PE and the effects of a variety of dietary fats with varying proportio ns of saturated and unsaturated fatty acids on membrane composition, e icosanoid production and cytokine production in thioglycollate-elicite d rat macrophages. The data obtained indicates that the greatest degre e of modulation by dietary fats on cytokine production was observed af ter 8 weeks feeding and at this time, the total diacyl species contain ing linoleic acid (18:2 n-6) and arachidonic acid (20:4 n-6) at the sn -2 position related in a curvilinear fashion to total 18:2 n-6 intake and that IL1 and IL6 production related in a curvilinear fashion to th e total diacyl species with 20:4 and 18:2 at the sn-2 position. After 4 weeks of feeding, fish and olive oils enhanced production of IL6 and LTB(4), however, while IL1 production, after 8 weeks of dietary treat ment, was greatest from macrophages of animals fed corn and olive oils , PGE(2) production was greatest in the former group and LTB(4) produc tion in the latter. Thus an eicosanoid effect may explain the modulato ry influence of olive oil and IL1 production but, cannot explain the e ffect of corn oil on production of the cytokine. The data from the pre sent study provides some insight into how dietary fats could provide t herapy for conditions in which inflammatory cytokines are implicated.