INFUSION OF EPA AND DHA LIPID EMULSIONS - EFFECTS ON HEART LIPIDS ANDTOLERANCE TO ISCHEMIA-REPERFUSION IN THE ISOLATED RAT-HEART

The aim of the present study was to examine the effect of acute infusi on of lipid emulsions enriched with either docosahexaenoic acid (DHA) or eicosapentaenoic acid (EPA) on heart lipids, tolerance to infusion and to ischaemia-reperfusion. Isolated rat hearts were subjected to a 10 min lipid infusion period prior to 25 min of total global ischaemia and 30 min of reperfusion. Effects on physiology and metabolism were recorded during infusion and reperfusion. A more than doubled increase of DHA and a 12-fold increase of EPA in terms of relative concentrati on was demonstrated in the free fatty acid fraction after infusion wit h the respective triglyceride emulsions, without any profound change i n physiology. High levels of DHA were associated with a reduced recove ry of left ventricular developed pressure (LVDP) and increased release of lactate dehydrogenase (LDH) during reperfusion, while the hearts i nfused with the EPA-emulsion showed a recovery comparable to the contr ol group. Heart lipid peroxidation, evaluated by release of thiobarbit uric acid reactive substances (TBARS) in effluate, was about 4-fold hi gher in the DHA-group compared to the EPA-group during start of reperf usion and may in part explain the reduced recovery observed in these h earts.