CONVERSIONS OF NON-BIOLOGICAL POLYUNSATURATED FATTY ACIDS IN RAT LIVER

1. 1. 7,10,13,16-Nonadecatetraenoic, 6,9,12,15,18-heneicosapentaenoic, 6,9,12,15-eicosatetraenoic, and 6,9,12,15-heneicosatetraenoic acids were prepared labeled with 14C. They were administered to rats deficient in essential fatty acids and their metabolism was compared with that of 5,8,11,14-eicosatetraenoic (arachidonic) and 4,7,10,13,16,19-docosahexaenoic acids. 2. 2. All these acids and their conversion products were incorporated mainly into phospholipids. In phosphatidyl cholines they were in position 2. 3. 3. Incorporation of polyunsaturated acids was close to 8% with all non-biological acids and with arachidonic acid. Incorporation of 4,7,10,13,16.19-docosahexaenoic acid was 16%. The extent of conversion depended on the structure of the acids. Docosahexaenoic and arachidonic acid formed the least amounts of conversion products. 4. 4. Highest conversion products of all non-biological acids had the proximal structure 5,8,... and among them 5,8, 11,14,17-docosapentaenoic acid, which derived from 6,9,12,15-eicosatetraenoic acid, was prominent in amount. © 1969.