RETROCONVERSION OF DOCOSAHEXAENOIC ACID IN RAT

1. 1. Uniformly 14C-labeled 4,7,10,13,16,19-docosahexaenoic acid was fed to normal rats and to rats at two stages of essential fatty acid deficiency. All groups incorporated about 17% of 14C fed into liver lipids. Normal rats retroconverted the hexaenoic acid to 7,10,13,16,19-docosapentaenoic and 5,8,11,14,17-eicosapentaenoic acids. These three acids were in phospholipids and, to about 20%, in triglycerides. The deficient rats retroconverted the hexaenoic acid to a much lesser extent and radioactivity in their triglycerides was much lower. 2. 2. The radioactivity in the carboxyl groups of 4,7,10,13,16,19-docosahexaenoic and 5,8,11,14,17-eicosapentaenoic acids corresponded closely to an even distribution of 4C in the chain. However, radioactivity in the carboxyl group of 7,10,13,16,19-docosapentaenoic acid was much lower than calculated for even distribution. At least 75% of this acid must have been reconstituted from a C20 chain. © 1969.