title: Low linoleic acid may facilitate Δ6 desaturase activity and docosahexaenoic acid accretion in human fetal development.
abstract: The n-3 and n-6 fatty acids are transferred across the placenta with consistently higher 22:6n-3 and lower 18:2n-6 in fetal than maternal plasma. This study sought to determine whether maternal and fetal cord blood red blood cell (RBC) phospholipid fatty acids show similar saturation with 22:6n-3, and also addressed the relationship between 18:2n-6 and Δ6 desaturase product/precursor ratios for 97 mothers and newborns. Despite higher fetal than maternal plasma phospholipid 22:6n-3, the maternal and fetal RBC phospholipid 22:6n-3 showed similar curvilinear relationships to the plasma phospholipid 22:6n-3. Risk of failure to achieve high RBC phospholipid 22:6n-3 increased sharply below a plasma phospholipid 22:6n-3 of 6.5g/100g fatty acids. Higher maternal and fetal 18:2n-6 was associated with lower RBC phospholipid 22:6n-3/22:5n-3, 22:5n-6/22:4n-6 and 18:3n-6/18:2n-6. These findings suggest low placental transfer of 18:2n-6 may be a specific mechanism to prevent inhibition of fetal Δ6 desaturase and facilitate fetal cellular phospholipid 22:6n-3 accretion.
authors.affiliation: Nutrition and Metabolism Research Program, Child and Family Research Institute, Department of Paediatrics, University of British Columbia, 950 West 28th Ave., Vancouver, B.C., Canada V5Z 4H4.
authors.forename: E M
authors.initials: EM
authors.lastname: Novak
authors.forename: D J
authors.initials: DJ
authors.lastname: King
authors.forename: S M
authors.initials: SM
authors.lastname: Innis
mesh_terms: D000328:Adult; D004281:Docosahexaenoic Acids / Q000097:blood* / Q000378:metabolism; D044943:Fatty Acid Desaturases / Q000378:metabolism*; D043371:Fatty Acids, Omega-6 / Q000097:blood / Q000378:metabolism; D005260:Female; D047109:Fetal Development; D005333:Fetus / Q000378:metabolism*; D006801:Humans; D019787:Linoleic Acid / Q000097:blood*; D010920:Placenta / Q000378:metabolism*; D011247:Pregnancy
chemical_list: D043371:Fatty Acids, Omega-6; D004281:Docosahexaenoic Acids; D019787:Linoleic Acid; D044943:Fatty Acid Desaturases; C533241:FADS2 protein, human