Changes of arachidonic acid and n-3 polyunsaturated fatty acids of phospholipid classes in liver, plasma and platelets during dietary fat manipulation.
When rats adapted to a fat-free diet were fed a corn oil diet, endogenous n-9 eicosatrienoic acid (the major polyunsaturated fatty acid) at the C-2 position of both phosphatidylcholine and phosphatidylethanolamine was quickly substituted by arachidonic acid in liver, plasma and platelets. Comparably, under a fish oil diet, the n-9 was quickly substituted by n-3 polyunsaturated fatty acids (eicosapentaenoic acid and docosahexaenoic acid). In both cases the n-9 almost disappeared in 6 days. On the other hand, when the dietary process was reversed, arachidonic acid in both the phospholipid classes (especially in phosphatidylcholine) decreased more slowly than the n-3 in the platelets and the liver mitochondria and microsomes. In platelets, even in linoleate-deficient rats, much arachidonic acid remained. However, arachidonic acid decreased similarly to the n-3 in the plasma. These results may reveal the physiological significance of arachidonic acid in membrane phospholipids, the replacement of arachidonic acid by the n-3 and the limitation of the replacement.
D000818:Animals; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000378:metabolism*; D001792:Blood Platelets / Q000378:metabolism*; D004041:Dietary Fats / Q000378:metabolism*; D005231:Fatty Acids, Unsaturated / Q000097:blood / Q000378:metabolism*; D008099:Liver / Q000378:metabolism*; D008297:Male; D010743:Phospholipids / Q000378:metabolism*; D051381:Rats
D001095:Arachidonic Acids; D004041:Dietary Fats; D005231:Fatty Acids, Unsaturated; D010743:Phospholipids; D016718:Arachidonic Acid