title: Competitive incorporation of dietary omega-3 and omega-6 polyunsaturated fatty acids into the tissue phospholipids in rats.
abstract: The incorporation of dietary omega-3 and omega-6 polyunsaturated fatty acids into the phospholipids of the liver, plasma and heart was studied by feeding rats with diets of increasing amounts of fish oil and/or corn oil up to 5% each for 2 weeks. Irrespective of the sources and amounts of dietary fat, total unsaturated fatty acids were 53-60% of phospholipid fatty acids in liver and plasma, and were 70-73% in heart. In all the animals either given or not given unsaturated fatty acid in diet, the sums of polyunsaturated fatty acids with more than three double bonds such as arachidonic acid, omega-3 polyunsaturated fatty acids and endogenous omega-9 eicosatrienoic acid were always 31-35, 18-20 and 30-38% in liver, plasma and heart, respectively. Dietary omega-3 unsaturated fatty acids and arachidonic acid appeared to be comparably incorporated into the phospholipids and substituted for each other in the phospholipids. These data may suggest that omega-3 polyunsaturated fatty acids compete with arachidonic acid for the C-2 position of the phospholipids.
mesh_terms: D000818:Animals; D004041:Dietary Fats / Q000008:administration & dosage*; D005227:Fatty Acids / Q000378:metabolism; D005231:Fatty Acids, Unsaturated / Q000008:administration & dosage / Q000378:metabolism*; D005395:Fish Oils / Q000008:administration & dosage*; D008099:Liver / Q000378:metabolism; D008297:Male; D009206:Myocardium / Q000378:metabolism; D009928:Organ Specificity; D010743:Phospholipids / Q000096:biosynthesis*; D051381:Rats; D011919:Rats, Inbred Strains; D003313:Zea mays
chemical_list: D004041:Dietary Fats; D005227:Fatty Acids; D005231:Fatty Acids, Unsaturated; D005395:Fish Oils; D010743:Phospholipids