COMPARATIVE EFFECTS OF EICOSAPENTAENOIC ACID AND DOCOSAHEXAENOIC ACIDON N-6 AND N-3 FATTY-ACID PROFILES OF PHOSPHOLIPID CLASSES IN SEVERALTISSUES OF RATS FED A HYPERTRIGLYCERIDEMIC DIET

Dietary hypertriglyceridemic rats were treated with refined eicosapent aenoic acid (EPA) and docosahexaenoic acid (DHA), and changes in the n -6 and n-3 polyunsaturated fatty acid (PUFA) profiles in phospholipid (PL) classes in their tissues were analyzed in various aspects. The ef fects of EPA on the PUFA profiles in tissue PL classes were different from those of DHA. The effects were manifested differently depending o n tissues and on the PL classes even in the same tissue. A decrease in the proportion of n-6 PUFA and an increase in the proportion of n-3 P UFA were both marked, particularly in the liver and heart, due to trea tment with EPA and DHA; whereas these changes were somewhat slighter i n the testes and were hardly observed in the brain. The variation patt ern of tissue difference in the individual PUFA of each PL class diffe red, depending on the kind of PUFA, among the control, EPA, and DHA gr oups. The variation pattern of PL class difference in the individual P UFA of each tissue showed a similar tendency. Suppression of metabolic conversion from linoleic acid to arachidonic acid was not uniform dep ending on the tissue and also on the PL class, but the effect of DHA w as more intense compared with that of EPA. On the other hand, the rati o of n-3 PUFA/total PUFA (n-3/PUFA) was largest in phosphatidylethanol amine, following by phosphatidylcholine and cardiolipin, in all the ti ssues, and was larger in the DHA group than in the EPA group. These fi ndings suggest that a large uptake of n-3 PUFA by the liver PC and PE classes may decrease the secretion of VLDL-TG from the liver and may b e related to the decrease of serum triglyceride.