DIETARY OMEGA-3 AND OMEGA-9 FATTY-ACIDS UNIQUELY ENHANCE ALLOGRAFT SURVIVAL IN CYCLOSPORINE-TREATED AND DONOR-SPECIFIC TRANSFUSION-TREATED RATS

Background. Both laboratory and clinical studies have shown that dieta ry lipids may affect immunologic responses. This study was conducted t o compare different classes of long-chain unsaturated fatty acids for their effect on allograft survival in animals receiving a donor-specif ic transfusion and a short course of low-dose cyclosporine (CsA). Meth ods. Heterotopic ACI strain cardiac allografts were transplanted to Le wis strain rat recipients given diets with different lipid composition . In experiment 1, animals received CsA for 14 days and different diet s were enriched with lipids with high concentrations of omega-3, omega -6, or omega-9 fatty acids. In experiment 2, animals received CsA for only 8 days and different diets were enriched with corn oil (omega-6), canola oil (omega-3 and omega-9), fish oil (omega-3) or a mixture of sunflower oil and fish oil (omega-3 and omega-9). Results. In experime nt 1, animals receiving the diet with 30% sunflower oil had the best a llograft survival (200+/-42 days vs. 53+/-8 days for regular chow plus donor-specific transfusion and CsA, P<0.05), In experiment 2, diets c ontaining canola oil (a mixture of omega-3 and omega-9 fatty acids) we re associated with the best survival (P=0.0011 vs. regular chow). Conc lusion. Dietary omega-3 and omega-9 fatty acids both enhanced cardiac allograft survival in a stringent rat strain combination. Canola oil i s a convenient oil for administering both alpha-linoleic acid (omega-3 ) and oleic acid (omega-9) in a palatable form for human consumption. Further investigation of the potential usefulness of lipids in transpl ant therapy is warranted.