INFLUENCE OF DIETARY POLYUNSATURATED FATTY-ACIDS ON AORTIC AND PLATELET FATTY-ACID COMPOSITION IN THE RAT

The effects of 18-carbon chain w-9, w-6 and w-3 fatty acid enriched diets on aortic and platelet fatty acid composition were studied in male Sprague-Dawley rats. Purified diets containing 11 wt % of either sesame oil (SES) rich in 18:1w9, borage oil (BOR) rich in 18:3w6 or a blend of linseed and saf- flower oils (LSO/SFO) rich in 18:3w3 were administered for 7 weeks. All diets provided comparable amounts of the essential fatty acid 18:2w6. Total lipids from aortic tissue and plate- lets were extracted, methylated and analyzed by gas chromatography. In general, the tissue fatty acid composition reflected the type of dietary fat. The SES diet resulted in increased levels of 18:1w9 whereas the BOR diet increased 18:3w6 and the LSO/SFO diet increased 18:3w3 in aortic and platelet lipids. However, the BOR diet also resulted in an increase in the longer chain metabolites 20:3w6 and 20:4w6. The LSO/SFO-based diet elevated the levels of 20:5w3 and 22:6w3. These results suggest that the profile of 20-carbon chain polyunsaturated fatty acids can be modified in vascular tissue and platelets by diets enriched with 18-carbon w-6 and w-3 fatty acids.