INTERCONVERSIONS AND DISTINCT METABOLIC-FATE OF EICOSAPENTAENOIC, DOCOSAPENTAENOIC AND DOCOSAHEXAENOIC ACIDS IN BOVINE AORTIC ENDOTHELIAL-CELLS

The anti-aggregatory activity of endothelial cells being affected by e icosapentaenoic (EPA, 20:5(n - 3)) and docosahexaenoic (DHA, 22:6(n - 3)) acids, the two main polyunsaturated fatty acids of fish oil, these fatty acids, as well as their intermediary, docosapentaenoic acid (DP A, 22:5(n - 3)), were investigated with respect to their metabolism. P rimary cultured bovine aortic endothelial cells were supplemented for 22 h at 37 degrees C with either n - 3 fatty acid, and the fatty acids of cell media, of cell lipid classes, and of choline and ethanolamine glycerophospholipids (PC and PE) were quantified. Endothelial cells c onverted each of the three fatty acids into the two others. They were found esterified in cell lipids and partly released in cell media, the respective parts varying according to the fatty acid. For instance, h alf of the DPA formed from EPA and two third of the EPA formed from DP A were released in the media. Moreover, the DHA formed from EPA and DP A was not esterified but released in media. In addition, the esterifie d counterparts were found in either PC or PE, depending on whether the y were added or formed by conversions. It is concluded that EPA, DPA a nd DHA are actively interconverted each others, and differ substantial ly in terms of distribution between media and cells, and within phosph olipid classes.