title: Whole body synthesis rates of DHA from α-linolenic acid are greater than brain DHA accretion and uptake rates in adult rats.
abstract: Docosahexaenoic acid (DHA) is important for brain function, however, the exact amount required for the brain is not agreed upon. While it is believed that the synthesis rate of DHA from α-linolenic acid (ALA) is low, how this synthesis rate compares with the amount of DHA required to maintain brain DHA levels is unknown. The objective of this work was to assess whether DHA synthesis from ALA is sufficient for the brain. To test this, rats consumed a diet low in n-3 PUFAs, or a diet containing ALA or DHA for 15 weeks. Over the 15 weeks, whole body and brain DHA accretion was measured, while at the end of the study, whole body DHA synthesis rates, brain gene expression, and DHA uptake rates were measured. Despite large differences in body DHA accretion, there was no difference in brain DHA accretion between rats fed ALA and DHA. In rats fed ALA, DHA synthesis and accretion was 100-fold higher than brain DHA accretion of rats fed DHA. Also, ALA-fed rats synthesized approximately 3-fold more DHA than the DHA uptake rate into the brain. This work indicates that DHA synthesis from ALA may be sufficient to supply the brain.
authors.affiliation: Department of Nutritional Sciences, University of Toronto, Toronto, Ontario M5S 3E2, Canada.
authors.forename: Anthony F
authors.initials: AF
authors.lastname: Domenichiello
authors.forename: Chuck T
authors.initials: CT
authors.lastname: Chen
authors.forename: Marc-Olivier
authors.initials: MO
authors.lastname: Trepanier
authors.forename: P Mark
authors.initials: PM
authors.lastname: Stavro
authors.forename: Richard P
authors.initials: RP
authors.lastname: Bazinet
mesh_terms: D000284:Administration, Oral; D000818:Animals; D001810:Blood Volume; D001921:Brain / Q000378:metabolism*; D004032:Diet; D004281:Docosahexaenoic Acids / Q000008:administration & dosage / Q000096:biosynthesis* / Q000493:pharmacokinetics; D005231:Fatty Acids, Unsaturated / Q000378:metabolism; D050356:Lipid Metabolism; D008297:Male; D009928:Organ Specificity; D051381:Rats; D020318:Rats, Long-Evans; D059467:Transcriptome; D017962:alpha-Linolenic Acid / Q000378:metabolism*
chemical_list: D005231:Fatty Acids, Unsaturated; D017962:alpha-Linolenic Acid; D004281:Docosahexaenoic Acids
keywords: a-linolenic-acid; brain; conversion; docosahexaenoic acid; kinetics; liver; synthesis